diff --git a/lib/xwidgets/accelerator.c b/lib/xwidgets/accelerator.c
index 0c96925..2a27836 100644
--- a/lib/xwidgets/accelerator.c
+++ b/lib/xwidgets/accelerator.c
@@ -30,7 +30,7 @@
 
 #include "xt.h"
 
-XtAccelerators Get_Accelerators (a) Object a; {
+XtAccelerators Get_Accelerators (Object a) {
     register char *s;
     XtAccelerators ret;
     Alloca_Begin;
@@ -42,14 +42,14 @@ XtAccelerators Get_Accelerators (a) Object a; {
     return ret;
 }
 
-static Object P_Install_Accelerators (dst, src) Object dst, src; {
+static Object P_Install_Accelerators (Object dst, Object src) {
     Check_Widget (dst);
     Check_Widget (src);
     XtInstallAccelerators (WIDGET(dst)->widget, WIDGET(src)->widget);
     return Void;
 }
 
-static Object P_Install_All_Accelerators (dst, src) Object dst, src; {
+static Object P_Install_All_Accelerators (Object dst, Object src) {
     Check_Widget (dst);
     Check_Widget (src);
     XtInstallAllAccelerators (WIDGET(dst)->widget, WIDGET(src)->widget);
@@ -57,7 +57,7 @@ static Object P_Install_All_Accelerators (dst, src) Object dst, src; {
 
 }
 
-elk_init_xt_accelerator () {
+void elk_init_xt_accelerator () {
     Define_Primitive (P_Install_Accelerators,
                         "install-accelerators",       2, 2, EVAL);
     Define_Primitive (P_Install_All_Accelerators,
diff --git a/lib/xwidgets/action.c b/lib/xwidgets/action.c
index 34e1bce..1a3130a 100644
--- a/lib/xwidgets/action.c
+++ b/lib/xwidgets/action.c
@@ -40,16 +40,14 @@ typedef struct action {
 ACTION *actions;
 
 /*ARGSUSED*/
-static void Dummy_Action (w, ep, argv, argc) Widget w; XEvent *ep;
-        String *argv; int *argc; {
+static void Dummy_Action (Widget w, XEvent *ep, String *argv, int *argc) {
 }
 
-void Action_Hook (w, client_data, name, ep, argv, argc)
-        Widget w; XtPointer client_data; char *name; XEvent *ep;
-        char **argv; int *argc; {
+void Action_Hook (Widget w, XtPointer client_data, char *name, XEvent *ep,
+                  char **argv, int *argc) {
     ACTION *ap;
     Object args, params, tail;
-    register i;
+    register int i;
     GC_Node3;
 
     for (ap = actions; ap; ap = ap->next) {
@@ -74,7 +72,7 @@ void Action_Hook (w, client_data, name, ep, argv, argc)
     }
 }
 
-static Object P_Context_Add_Action (c, s, p) Object c, s, p; {
+static Object P_Context_Add_Action (Object c, Object s, Object p) {
     ACTION *ap;
     XtActionsRec a;
 
@@ -92,10 +90,10 @@ static Object P_Context_Add_Action (c, s, p) Object c, s, p; {
     return Void;
 }
 
-void Free_Actions (con) XtAppContext con; {
+void Free_Actions (XtAppContext con) {
     register ACTION *p, **pp;
 
-    for (pp = &actions; p = *pp; ) {
+    for (pp = &actions; (p = *pp); ) {
         if (p->con == con) {
             Deregister_Function (p->num);
             XtFree (p->name);
@@ -105,6 +103,6 @@ void Free_Actions (con) XtAppContext con; {
     }
 }
 
-elk_init_xt_action () {
+void elk_init_xt_action () {
     Define_Primitive (P_Context_Add_Action, "context-add-action", 3, 3, EVAL);
 }
diff --git a/lib/xwidgets/callback.c b/lib/xwidgets/callback.c
index c718b15..baa1aec 100644
--- a/lib/xwidgets/callback.c
+++ b/lib/xwidgets/callback.c
@@ -30,18 +30,20 @@
 
 #include "xt.h"
 
+void Remove_All_Callbacks (Widget w);
+
 typedef struct {
     PFX2S converter;
     int num;
 } CLIENT_DATA;
 
-Object Get_Callbackfun (c) XtPointer c; {
+Object Get_Callbackfun (XtPointer c) {
     register CLIENT_DATA *cd = (CLIENT_DATA *)c;
     return cd ? Get_Function (cd->num) : False;
 }
 
-static void Callback_Proc (w, client_data, call_data) Widget w;
-        XtPointer client_data, call_data; {
+static void Callback_Proc (Widget w, XtPointer client_data,
+                           XtPointer call_data) {
     register CLIENT_DATA *cd = (CLIENT_DATA *)client_data;
     Object args;
     GC_Node;
@@ -56,8 +58,8 @@ static void Callback_Proc (w, client_data, call_data) Widget w;
 }
 
 /*ARGSUSED*/
-void Destroy_Callback_Proc (w, client_data, call_data) Widget w;
-        XtPointer client_data, call_data; {
+void Destroy_Callback_Proc (Widget w, XtPointer client_data,
+                            XtPointer call_data) {
     Object x;
 
     x = Find_Object (T_Widget, (GENERIC)0, Match_Xt_Obj, w);
@@ -77,13 +79,13 @@ void Destroy_Callback_Proc (w, client_data, call_data) Widget w;
  * must be called to remove the Destroy_Callback_Proc() and put
  * it back to the end of the callback list.
  */
-void Fiddle_Destroy_Callback (w) Widget w; {
+void Fiddle_Destroy_Callback (Widget w) {
     XtRemoveCallback (w, XtNdestroyCallback, Destroy_Callback_Proc,
         (XtPointer)0);
     XtAddCallback (w, XtNdestroyCallback, Destroy_Callback_Proc, (XtPointer)0);
 }
 
-void Check_Callback_List (x) Object x; {
+void Check_Callback_List (Object x) {
     Object tail;
 
     Check_List (x);
@@ -91,9 +93,9 @@ void Check_Callback_List (x) Object x; {
         Check_Procedure (Car (tail));
 }
 
-static Object P_Add_Callbacks (w, name, cbl) Object w, name, cbl; {
+static Object P_Add_Callbacks (Object w, Object name, Object cbl) {
     register char *s;
-    register n;
+    register int n;
     XtCallbackList callbacks;
     Alloca_Begin;
 
@@ -114,10 +116,10 @@ static Object P_Add_Callbacks (w, name, cbl) Object w, name, cbl; {
     return Void;
 }
 
-void Fill_Callbacks (src, dst, n, conv) Object src; XtCallbackList dst;
-        register n; PFX2S conv; {
+void Fill_Callbacks (Object src, XtCallbackList dst, register int n,
+                     PFX2S conv) {
     register CLIENT_DATA *cd;
-    register i, j;
+    register int i, j;
     Object tail;
 
     for (i = 0, tail = src; i < n; i++, tail = Cdr (tail)) {
@@ -130,12 +132,12 @@ void Fill_Callbacks (src, dst, n, conv) Object src; XtCallbackList dst;
     }
 }
 
-Remove_All_Callbacks (w) Widget w; {
+void Remove_All_Callbacks (Widget w) {
     Arg a[1];
     XtCallbackList c;
     XtResource *r;
     int nr, nc;
-    register i, j;
+    register int i, j;
 
     Get_All_Resources (0, w, XtClass (w), &r, &nr, &nc);
     for (j = 0; j < nr; j++) {
@@ -154,6 +156,6 @@ Remove_All_Callbacks (w) Widget w; {
     XtFree ((char *)r);
 }
 
-elk_init_xt_callback () {
+void elk_init_xt_callback () {
     Define_Primitive (P_Add_Callbacks, "add-callbacks", 3, 3, EVAL);
 }
diff --git a/lib/xwidgets/class.c b/lib/xwidgets/class.c
index 8fa2183..81a9ef6 100644
--- a/lib/xwidgets/class.c
+++ b/lib/xwidgets/class.c
@@ -54,7 +54,7 @@ Generic_Simple_Equal (Class, CLASS, wclass)
 
 Generic_Print (Class, "#[class %s]", CLASS(x)->name)
 
-Object Make_Class (class, name) WidgetClass class; char *name; {
+Object Make_Class (WidgetClass class, char *name) {
     Object c;
 
     c = Find_Object (T_Class, (GENERIC)0, Match_Xt_Obj, class);
@@ -70,7 +70,7 @@ Object Make_Class (class, name) WidgetClass class; char *name; {
     return c;
 }
 
-Object Make_Widget_Class (class) WidgetClass class; {
+Object Make_Widget_Class (WidgetClass class) {
     register CLASS_INFO *p;
 
     for (p = ctab; p < clast; p++)
@@ -80,7 +80,7 @@ Object Make_Widget_Class (class) WidgetClass class; {
     /*NOTREACHED*/
 }
 
-static Object P_Find_Class (name) Object name; {
+static Object P_Find_Class (Object name) {
     register CLASS_INFO *p;
     register char *s = Get_Strsym (name);
 
@@ -92,7 +92,7 @@ static Object P_Find_Class (name) Object name; {
     /*NOTREACHED*/
 }
 
-static Object P_Class_Existsp (name) Object name; {
+static Object P_Class_Existsp (Object name) {
     register CLASS_INFO *p;
     register char *s = Get_Strsym (name);
 
@@ -103,7 +103,7 @@ static Object P_Class_Existsp (name) Object name; {
     return False;
 }
 
-char *Class_Name (class) WidgetClass class; {
+char *Class_Name (WidgetClass class) {
     register CLASS_INFO *p;
 
     for (p = ctab; p < clast && p->class != class; p++)
@@ -113,8 +113,8 @@ char *Class_Name (class) WidgetClass class; {
     return p->name;
 }
 
-void Get_Sub_Resource_List (class, rp, np) WidgetClass class;
-        XtResourceList *rp; Cardinal *np; {
+void Get_Sub_Resource_List (WidgetClass class, XtResourceList *rp,
+                            Cardinal *np) {
     register CLASS_INFO *p;
 
     for (p = ctab; p < clast && p->class != class; p++)
@@ -125,23 +125,22 @@ void Get_Sub_Resource_List (class, rp, np) WidgetClass class;
     *rp = p->sub_resources;
 }
 
-static Object P_Class_Resources (c) Object c; {
+static Object P_Class_Resources (Object c) {
     Check_Type (c, T_Class);
     return Get_Resources (CLASS(c)->wclass, XtGetResourceList, 1);
 }
 
-static Object P_Class_Constraint_Resources (c) Object c; {
+static Object P_Class_Constraint_Resources (Object c) {
     Check_Type (c, T_Class);
     return Get_Resources (CLASS(c)->wclass, XtGetConstraintResourceList, 1);
 }
 
-static Object P_Class_Sub_Resources (c) Object c; {
+static Object P_Class_Sub_Resources (Object c) {
     Check_Type (c, T_Class);
     return Get_Resources (CLASS(c)->wclass, Get_Sub_Resource_List, 0);
 }
 
-void Define_Class (name, class, r, nr) char *name; WidgetClass class;
-        XtResourceList r; {
+void Define_Class (char *name, WidgetClass class, XtResourceList r, int nr) {
     Set_Error_Tag ("define-class");
     if (clast == ctab+MAX_CLASS)
         Primitive_Error ("too many widget classes");
@@ -166,7 +165,7 @@ void Define_Class (name, class, r, nr) char *name; WidgetClass class;
     clast++;
 }
 
-void Define_Callback (cl, s, has_arg) char *cl, *s; {
+void Define_Callback (char *cl, char *s, int has_arg) {
     register CLASS_INFO *p;
 
     Set_Error_Tag ("define-callback");
@@ -182,8 +181,7 @@ void Define_Callback (cl, s, has_arg) char *cl, *s; {
     Primitive_Error ("undefined class");
 }
 
-PFX2S Find_Callback_Converter (c, name, sname) WidgetClass c; char *name;
-        Object sname; {
+PFX2S Find_Callback_Converter (WidgetClass c, char *name, Object sname) {
     register CLASS_INFO *p;
     register CALLBACK_INFO *q;
     PFX2S conv;
@@ -208,7 +206,7 @@ PFX2S Find_Callback_Converter (c, name, sname) WidgetClass c; char *name;
                             if (conv == 0) {
                                 sprintf (msg,
                                     "no callback converter for %s or %s",
-                                        s1, s2, name);
+                                        s1, s2);
                                 Primitive_Error (msg);
                             }
                         }
@@ -221,7 +219,7 @@ PFX2S Find_Callback_Converter (c, name, sname) WidgetClass c; char *name;
     /*NOTREACHED*/
 }
 
-elk_init_xt_class () {
+void elk_init_xt_class () {
     Generic_Define (Class, "class", "class?");
     Define_Primitive (P_Find_Class,        "find-class",        1, 1, EVAL);
     Define_Primitive (P_Class_Resources,   "class-resources",   1, 1, EVAL);
diff --git a/lib/xwidgets/classname.c b/lib/xwidgets/classname.c
index 27e5a44..01084d7 100644
--- a/lib/xwidgets/classname.c
+++ b/lib/xwidgets/classname.c
@@ -33,7 +33,7 @@
 #include <X11/IntrinsicP.h>
 #include <X11/CoreP.h>
 
-Object Xt_Class_Name (class) WidgetClass class; {
+Object Xt_Class_Name (WidgetClass class) {
     return Make_String (class->core_class.class_name,
         strlen (class->core_class.class_name));
 }
diff --git a/lib/xwidgets/context.c b/lib/xwidgets/context.c
index ba31eff..a709712 100644
--- a/lib/xwidgets/context.c
+++ b/lib/xwidgets/context.c
@@ -52,7 +52,7 @@ Generic_Equal (Context, CONTEXT, context)
 
 Generic_Print (Context, "#[context %lu]", POINTER(x))
 
-static Object Internal_Make_Context (finalize, context) XtAppContext context; {
+static Object Internal_Make_Context (int finalize, XtAppContext context) {
     Object c;
 
     c = Find_Object (T_Context, (GENERIC)0, Match_Xt_Obj, context);
@@ -71,15 +71,15 @@ static Object Internal_Make_Context (finalize, context) XtAppContext context; {
 }
 
 /* Backwards compatibility: */
-Object Make_Context (context) XtAppContext context; {
+Object Make_Context (XtAppContext context) {
     return Internal_Make_Context (1, context);
 }
 
-Object Make_Context_Foreign (context) XtAppContext context; {
+Object Make_Context_Foreign (XtAppContext context) {
     return Internal_Make_Context (0, context);
 }
 
-void Check_Context (c) Object c; {
+void Check_Context (Object c) {
     Check_Type (c, T_Context);
     if (CONTEXT(c)->free)
         Primitive_Error ("invalid context: ~s", c);
@@ -89,7 +89,7 @@ static Object P_Create_Context () {
     return Make_Context (XtCreateApplicationContext ());
 }
 
-static Object P_Destroy_Context (c) Object c; {
+static Object P_Destroy_Context (Object c) {
     Check_Context (c);
     Free_Actions (CONTEXT(c)->context);
     XtDestroyApplicationContext (CONTEXT(c)->context);
@@ -98,12 +98,12 @@ static Object P_Destroy_Context (c) Object c; {
     return Void;
 }
 
-static Object P_Initialize_Display (c, d, name, class)
-        Object c, d, name, class; {
+static Object P_Initialize_Display (Object c, Object d, Object name,
+                                    Object class) {
     register char *sn = 0, *sc = "", *sd = 0;
     Display *dpy;
     extern char **Argv;
-    extern First_Arg, Argc;
+    extern int First_Arg, Argc;
     int argc = Argc - First_Arg + 1;
 
     Argv[First_Arg-1] = "elk";
@@ -124,25 +124,27 @@ static Object P_Initialize_Display (c, d, name, class)
         (XrmOptionDescRec *)0, 0, &argc, &Argv[First_Arg-1]);
     Argc = First_Arg + argc - 1;
     if (dpy == 0)
+    {
         if (sd)
             Primitive_Error ("cannot open display ~s", d);
         else
             Primitive_Error ("cannot open display");
+    }
     return Make_Display (0, dpy);
 }
 
 /* Due to a bug in Xt this function drops core when invoked with a
  * display not owned by Xt.
  */
-static Object P_Display_To_Context (d) Object d; {
+static Object P_Display_To_Context (Object d) {
     Check_Type (d, T_Display);
     return
         Make_Context_Foreign (XtDisplayToApplicationContext (DISPLAY(d)->dpy));
 }
 
-static Object P_Set_Context_Fallback_Resources (argc, argv) Object *argv; {
+static Object P_Set_Context_Fallback_Resources (int argc, Object *argv) {
     register char **p = 0;
-    register i;
+    register int i;
     struct S_String *sp;
     Object con;
 
@@ -164,19 +166,20 @@ static Object P_Set_Context_Fallback_Resources (argc, argv) Object *argv; {
     return Void;
 }
 
-static Object P_Context_Main_Loop (c) Object c; {
+static Object P_Context_Main_Loop (Object c) {
     Check_Context (c);
     XtAppMainLoop (CONTEXT(c)->context);
     /*NOTREACHED*/
+    return Void;
 }
 
-static Object P_Context_Pending (c) Object c; {
+static Object P_Context_Pending (Object c) {
     Check_Context (c);
     return Bits_To_Symbols ((unsigned long)XtAppPending (CONTEXT(c)->context),
         1, XtIM_Syms);
 }
 
-static Object P_Context_Process_Event (argc, argv) Object *argv; {
+static Object P_Context_Process_Event (int argc, Object *argv) {
     XtInputMask mask = XtIMAll;
 
     Check_Context (argv[0]);
@@ -186,7 +189,7 @@ static Object P_Context_Process_Event (argc, argv) Object *argv; {
     return Void;
 }
 
-static Boolean Work_Proc (client_data) XtPointer client_data; {
+static Boolean Work_Proc (XtPointer client_data) {
     Object ret;
 
     ret = Funcall (Get_Function ((int)client_data), Null, 0);
@@ -195,9 +198,9 @@ static Boolean Work_Proc (client_data) XtPointer client_data; {
     return Truep (ret);
 }
 
-static Object P_Context_Add_Work_Proc (c, p) Object c, p; {
+static Object P_Context_Add_Work_Proc (Object c, Object p) {
     XtWorkProcId id;
-    register i;
+    register int i;
 
     Check_Context (c);
     Check_Procedure (p);
@@ -206,16 +209,15 @@ static Object P_Context_Add_Work_Proc (c, p) Object c, p; {
     return Make_Id ('w', (XtPointer)id, i);
 }
 
-static Object P_Remove_Work_Proc (id) Object id; {
+static Object P_Remove_Work_Proc (Object id) {
     XtRemoveWorkProc ((XtWorkProcId)Use_Id (id, 'w'));
     Deregister_Function (IDENTIFIER(id)->num);
     return Void;
 }
 
-static void Timeout_Proc (client_data, id)
-        XtPointer client_data; XtIntervalId *id; {
+static void Timeout_Proc (XtPointer client_data, XtIntervalId *id) {
     Object proc, args;
-    register i = (int)client_data;
+    register int i = (int)client_data;
 
     args = Cons (Make_Id ('t', (XtPointer)*id, i), Null);
     proc = Get_Function (i);
@@ -223,9 +225,9 @@ static void Timeout_Proc (client_data, id)
     (void)Funcall (proc, args, 0);
 }
 
-static Object P_Context_Add_Timeout (c, n, p) Object c, n, p; {
+static Object P_Context_Add_Timeout (Object c, Object n, Object p) {
     XtIntervalId id;
-    register i;
+    register int i;
 
     Check_Context (c);
     Check_Procedure (p);
@@ -235,15 +237,14 @@ static Object P_Context_Add_Timeout (c, n, p) Object c, n, p; {
     return Make_Id ('t', (XtPointer)id, i);
 }
 
-static Object P_Remove_Timeout (id) Object id; {
+static Object P_Remove_Timeout (Object id) {
     XtRemoveTimeOut ((XtIntervalId)Use_Id (id, 't'));
     Deregister_Function (IDENTIFIER(id)->num);
     return Void;
 }
 
 /*ARGSUSED*/
-static void Input_Proc (client_data, src, id) XtPointer client_data; int *src;
-        XtInputId *id; {
+static void Input_Proc (XtPointer client_data, int *src, XtInputId *id) {
     Object p, args;
     GC_Node2;
 
@@ -256,11 +257,11 @@ static void Input_Proc (client_data, src, id) XtPointer client_data; int *src;
     (void)Funcall (Cdr (p), args, 0);
 }
 
-static Object P_Context_Add_Input (argc, argv) Object *argv; {
+static Object P_Context_Add_Input (int argc, Object *argv) {
     Object c, src, p;
     XtInputId id;
     XtInputMask m;
-    register i;
+    register int i;
 
     c = argv[0], src = argv[1], p = argv[2];
     Check_Context (c);
@@ -285,13 +286,13 @@ static Object P_Context_Add_Input (argc, argv) Object *argv; {
     return Make_Id ('i', (XtPointer)id, i);
 }
 
-static Object P_Remove_Input (id) Object id; {
+static Object P_Remove_Input (Object id) {
     XtRemoveInput ((XtInputId)Use_Id (id, 'i'));
     Deregister_Function (IDENTIFIER(id)->num);
     return Void;
 }
 
-elk_init_xt_context () {
+void elk_init_xt_context () {
     Generic_Define (Context, "context", "context?");
     Define_Primitive (P_Create_Context,     "create-context",     0, 0, EVAL);
     Define_Primitive (P_Destroy_Context,    "destroy-context",    1, 1, EVAL);
diff --git a/lib/xwidgets/converter.c b/lib/xwidgets/converter.c
index 77b6350..a5e4ae9 100644
--- a/lib/xwidgets/converter.c
+++ b/lib/xwidgets/converter.c
@@ -41,7 +41,7 @@ typedef struct {
 
 static CONVERTER ctab[MAX_CONVERTER], *clast = ctab;
 
-void Define_Converter_To_Scheme (name, c) char *name; PFX2S c; {
+void Define_Converter_To_Scheme (char *name, PFX2S c) {
     Set_Error_Tag ("c->scheme");
     if (clast == ctab+MAX_CONVERTER)
         Primitive_Error ("too many converters");
@@ -51,7 +51,7 @@ void Define_Converter_To_Scheme (name, c) char *name; PFX2S c; {
     clast++;
 }
 
-void Define_Converter_To_C (name, c) char *name; PFS2X c; {
+void Define_Converter_To_C (char *name, PFS2X c) {
     Set_Error_Tag ("scheme->c");
     if (clast == ctab+MAX_CONVERTER)
         Primitive_Error ("too many converters");
@@ -61,7 +61,7 @@ void Define_Converter_To_C (name, c) char *name; PFS2X c; {
     clast++;
 }
 
-PFX2S Find_Converter_To_Scheme (name) char *name; {
+PFX2S Find_Converter_To_Scheme (char *name) {
     register CONVERTER *p;
 
     for (p = ctab; p < clast; p++)
@@ -70,7 +70,7 @@ PFX2S Find_Converter_To_Scheme (name) char *name; {
     return 0;
 }
 
-PFS2X Find_Converter_To_C (name) char *name; {
+PFS2X Find_Converter_To_C (char *name) {
     register CONVERTER *p;
 
     for (p = ctab; p < clast; p++)
diff --git a/lib/xwidgets/function.c b/lib/xwidgets/function.c
index 5f60db4..904a042 100644
--- a/lib/xwidgets/function.c
+++ b/lib/xwidgets/function.c
@@ -30,11 +30,11 @@
 
 #include "xt.h"
 
-static max_functions = 512;
+static int max_functions = 512;
 static Object Functions;
 
-int Register_Function (x) Object x; {
-    register i;
+int Register_Function (Object x) {
+    register int i;
     Object v;
     GC_Node;
 
@@ -53,15 +53,15 @@ int Register_Function (x) Object x; {
     return i;
 }
 
-Object Get_Function (i) int i; {
+Object Get_Function (int i) {
     return VECTOR(Functions)->data[i];
 }
 
-void Deregister_Function (i) int i; {
+void Deregister_Function (int i) {
     VECTOR(Functions)->data[i] = Null;
 }
 
-elk_init_xt_function () {
+void elk_init_xt_function () {
     Functions = Make_Vector (max_functions, Null);
     Global_GC_Link (Functions);
 }
diff --git a/lib/xwidgets/identifier.c b/lib/xwidgets/identifier.c
index 055aa1a..7ac320e 100644
--- a/lib/xwidgets/identifier.c
+++ b/lib/xwidgets/identifier.c
@@ -32,14 +32,14 @@
 
 Generic_Predicate (Identifier)
 
-static Identifier_Equal (x, y) Object x, y; {
+static int Identifier_Equal (Object x, Object y) {
     register struct S_Identifier *p = IDENTIFIER(x), *q = IDENTIFIER(y);
     return p->type == q->type && p->val == q->val && !p->free && !q->free;
 }
 
 Generic_Print (Identifier, "#[identifier %lu]", POINTER(x))
 
-Object Make_Id (type, val, num) XtPointer val; {
+Object Make_Id (int type, XtPointer val, int num) {
     Object i;
 
     i = Find_Object (T_Identifier, (GENERIC)0, Match_Xt_Obj, type, val);
@@ -55,7 +55,7 @@ Object Make_Id (type, val, num) XtPointer val; {
     return i;
 }
 
-XtPointer Use_Id (x, type) Object x; {
+XtPointer Use_Id (Object x, int type) {
     Check_Type (x, T_Identifier);
     if (IDENTIFIER(x)->type != type || IDENTIFIER(x)->free)
         Primitive_Error ("invalid identifier");
@@ -64,6 +64,6 @@ XtPointer Use_Id (x, type) Object x; {
     return IDENTIFIER(x)->val;
 }
 
-elk_init_xt_identifier () {
+void elk_init_xt_identifier () {
     Generic_Define (Identifier, "identifier", "identifier?");
 }
diff --git a/lib/xwidgets/mkwidget.scm b/lib/xwidgets/mkwidget.scm
index 6f97802..7f3e5ec 100644
--- a/lib/xwidgets/mkwidget.scm
+++ b/lib/xwidgets/mkwidget.scm
@@ -64,7 +64,7 @@
   (check-string 'c->scheme name 'name)
   (define c-name (scheme-to-c-name name))
   (string-set! c-name 0 #\S)
-  (format f "static Object ~a (x) XtArgVal x; {~%" c-name)
+  (format f "static Object ~a (XtArgVal x) {~%" c-name)
   (display body f)
   (format f "~%}~%~%")
   (define s
@@ -76,7 +76,7 @@
   (check-string 'scheme->c name 'name)
   (define c-name (scheme-to-c-name name))
   (string-set! c-name 0 #\C)
-  (format f "static XtArgVal ~a (x) Object x; {~%" c-name)
+  (format f "static XtArgVal ~a (Object x) {~%" c-name)
   (display body f)
   (format f "~%}~%~%")
   (define s
@@ -91,18 +91,11 @@
   (define c-name (scheme-to-c-name scheme-name))
   (format f "static Object ~a (" c-name)
   (do ((a args a)) ((null? a))
+    (display "Object " f)
     (display (car a) f)
     (set! a (cdr a))
     (if (not (null? a)) (display ", " f)))
-  (display ") " f)
-  (if (not (null? args))
-      (begin
-	(display "Object " f)
-	(do ((a args a)) ((null? a))
-	  (display (car a) f)
-	  (set! a (cdr a))
-	  (if (not (null? a)) (display ", " f)))
-	(display "; {" f)))
+  (display ") {" f)
   (newline f)
   (display body f)
   (format f "~%}~%~%")
@@ -161,7 +154,7 @@
 (load (car args))
 (if (not type-name)
     (error 'mkwidget "no widget type defined"))
-(format f "elk_init_~a_~a () {~%" widget-set type-name)
+(format f "void elk_init_~a_~a () {~%" widget-set type-name)
 (if (not (null? classes))
     (format f "    XtResourceList r = 0;~%"))
 (do ((c classes (cdr c))) ((null? c))
diff --git a/lib/xwidgets/motif/init.c b/lib/xwidgets/motif/init.c
index 12a95f0..6b75de6 100644
--- a/lib/xwidgets/motif/init.c
+++ b/lib/xwidgets/motif/init.c
@@ -30,6 +30,6 @@
 
 #include "scheme.h"
 
-elk_init_motif_init () {
+void elk_init_motif_init () {
     P_Provide (Intern ("motif-widgets.so"));
 }
diff --git a/lib/xwidgets/motif/list.d b/lib/xwidgets/motif/list.d
index 303f92c..011234b 100644
--- a/lib/xwidgets/motif/list.d
+++ b/lib/xwidgets/motif/list.d
@@ -33,7 +33,7 @@
 
 (prolog
 
-"static Object String_Table_To_Scheme (tab, len) XmString *tab; {
+"static Object String_Table_To_Scheme (XmString *tab, int len) {
     Object ret, tail;
     char *text;
     GC_Node2;
@@ -60,7 +60,7 @@
 
 (prolog
 
-"static Object Get_List_CB (p) XmListCallbackStruct *p; {
+"static Object Get_List_CB (XmListCallbackStruct *p) {
     Object ret, s;
     char *text;
     GC_Node2;
diff --git a/lib/xwidgets/motif/row-column.d b/lib/xwidgets/motif/row-column.d
index 1389def..a38d4e2 100644
--- a/lib/xwidgets/motif/row-column.d
+++ b/lib/xwidgets/motif/row-column.d
@@ -44,8 +44,8 @@
 
 (prolog
 
-"static void Post_Handler (w, client_data, event, unused) Widget w;
-	XtPointer client_data; XEvent *event; Boolean *unused; {
+"static void Post_Handler (Widget w, XtPointer client_data, XEvent *event,
+                          Boolean *unused) {
     unsigned int b;
     Arg a;
     XButtonPressedEvent *ep = (XButtonPressedEvent *)event;
@@ -61,7 +61,7 @@
 
 (prolog
 
-"static Object Get_Row_Column_CB (p) XmRowColumnCallbackStruct *p; {
+"static Object Get_Row_Column_CB (XmRowColumnCallbackStruct *p) {
     Object ret, s;
     GC_Node2;
 
diff --git a/lib/xwidgets/motif/scale.d b/lib/xwidgets/motif/scale.d
index e772b87..2137bba 100644
--- a/lib/xwidgets/motif/scale.d
+++ b/lib/xwidgets/motif/scale.d
@@ -33,7 +33,7 @@
 
 (prolog
 
-"static Object Get_Scale_CB (p) XmScaleCallbackStruct *p; {
+"static Object Get_Scale_CB (XmScaleCallbackStruct *p) {
     Object ret, s;
     extern SYMDESCR Reason_Syms[];
     GC_Node2;
diff --git a/lib/xwidgets/motif/scroll-bar.d b/lib/xwidgets/motif/scroll-bar.d
index 9b2b537..7d0e360 100644
--- a/lib/xwidgets/motif/scroll-bar.d
+++ b/lib/xwidgets/motif/scroll-bar.d
@@ -33,7 +33,7 @@
 
 (prolog
 
-"static Object Get_Scrollbar_CB (p) XmScrollBarCallbackStruct *p; {
+"static Object Get_Scrollbar_CB (XmScrollBarCallbackStruct *p) {
     Object ret, s;
     GC_Node2;
 
diff --git a/lib/xwidgets/motif/support.d b/lib/xwidgets/motif/support.d
index ba87d95..568bbc5 100644
--- a/lib/xwidgets/motif/support.d
+++ b/lib/xwidgets/motif/support.d
@@ -76,7 +76,7 @@
 
 (prolog
 
-"Object Get_Any_CB (p) XmAnyCallbackStruct *p; {
+"Object Get_Any_CB (XmAnyCallbackStruct *p) {
     Object args, ret;
     GC_Node2;
 
@@ -95,7 +95,7 @@
 
 (prolog
 
-"Object Get_Selection_CB (p) XmSelectionBoxCallbackStruct *p; {
+"Object Get_Selection_CB (XmSelectionBoxCallbackStruct *p) {
     Object ret, s;
     char *text;
     GC_Node2;
@@ -114,7 +114,7 @@
 
 (prolog
 
-"static XtArgVal Scheme_To_String_Table (x) Object x; {
+"static XtArgVal Scheme_To_String_Table (Object x) {
     Object t;
     char *s;
     XmString *tab;
diff --git a/lib/xwidgets/popup.c b/lib/xwidgets/popup.c
index 46b81bf..46f151d 100644
--- a/lib/xwidgets/popup.c
+++ b/lib/xwidgets/popup.c
@@ -37,7 +37,7 @@ static SYMDESCR Grab_Kind_Syms[] = {
     { 0, 0 }
 };
 
-static Object P_Create_Popup_Shell (argc, argv) Object *argv; {
+static Object P_Create_Popup_Shell (int argc, Object *argv) {
     ArgList a;
     char *name = 0;
     Object x, class, parent, ret;
@@ -61,20 +61,20 @@ static Object P_Create_Popup_Shell (argc, argv) Object *argv; {
     return ret;
 }
 
-static Object P_Popup (shell, grab_kind) Object shell, grab_kind; {
+static Object P_Popup (Object shell, Object grab_kind) {
     Check_Widget (shell);
     XtPopup (WIDGET(shell)->widget, Symbols_To_Bits (grab_kind, 0,
         Grab_Kind_Syms));
     return Void;
 }
 
-static Object P_Popdown (shell) Object shell; {
+static Object P_Popdown (Object shell) {
     Check_Widget (shell);
     XtPopdown (WIDGET(shell)->widget);
     return Void;
 }
 
-elk_init_xt_popup () {
+void elk_init_xt_popup () {
     Define_Primitive (P_Create_Popup_Shell, "create-popup-shell",
                                             2, MANY, VARARGS);
     Define_Primitive (P_Popup,   "popup",   2, 2, EVAL);
diff --git a/lib/xwidgets/resource.c b/lib/xwidgets/resource.c
index cb4d0db..bcb1dcf 100644
--- a/lib/xwidgets/resource.c
+++ b/lib/xwidgets/resource.c
@@ -48,7 +48,7 @@
 #define T_Cardinal           -10
 #define T_Accelerators       -11
 
-static Resource_To_Scheme_Type (t) register char *t; {
+static int Resource_To_Scheme_Type (register char *t) {
     if (streq (XtRAcceleratorTable, t))
         return T_Accelerators;
     else if (streq (XtRBackingStore, t))
@@ -102,8 +102,8 @@ static Resource_To_Scheme_Type (t) register char *t; {
     return T_Unknown;
 }
 
-void Get_All_Resources (sub, w, c, rp, np, cp) Widget w; WidgetClass c;
-        XtResource **rp; int *np, *cp; {
+void Get_All_Resources (int sub, Widget w, WidgetClass c, XtResource **rp,
+                        int *np, int *cp) {
     XtResource *r, *sr, *cr;
     int nr, snr = 0, cnr = 0;
 
@@ -126,10 +126,10 @@ void Get_All_Resources (sub, w, c, rp, np, cp) Widget w; WidgetClass c;
     }
 }
 
-void Convert_Args (ac, av, to, widget, class) Object *av; ArgList to;
-        Widget widget; WidgetClass class; {
+void Convert_Args (int ac, Object *av, ArgList to, Widget widget,
+                   WidgetClass class) {
     register char *name, *res;
-    register i, j, k;
+    register int i, j, k;
     Object arg, val;
     XtResource *r;
     int nr, nc;
@@ -274,9 +274,9 @@ done: ;
     XtFree ((char *)r);
 }
 
-Object Get_Values (w, ac, av) Widget w; Object *av; {
+Object Get_Values (Widget w, int ac, Object *av) {
     register char *name;
-    register i, j;
+    register int i, j;
     Object arg;
     XtResource *r;
     int nr, nc;
@@ -334,9 +334,9 @@ Object Get_Values (w, ac, av) Widget w; Object *av; {
 
         if (converter) {
             o = converter (*(XtArgVal *)val);
-        } else if (converter = Find_Converter_To_Scheme (argl[i].name)) {
+        } else if ((converter = Find_Converter_To_Scheme (argl[i].name))) {
             o = converter (*(XtArgVal *)val);
-        } else if (converter = Find_Converter_To_Scheme (r[j].resource_type)) {
+        } else if ((converter = Find_Converter_To_Scheme (r[j].resource_type))) {
             o = converter (*(XtArgVal *)val);
         } else if (t == T_String_Or_Symbol) {
             char *s = *(char **)val;
@@ -344,7 +344,7 @@ Object Get_Values (w, ac, av) Widget w; Object *av; {
             if (s == 0) s = "";
             o = Make_String (s, strlen (s));
         } else if (t == T_Callbacklist) {
-            register i, n;
+            register int i, n;
             Object ret, tail;
             XtCallbackList callbacks = *(XtCallbackList *)val;
             GC_Node;
@@ -422,7 +422,7 @@ Object Get_Values (w, ac, av) Widget w; Object *av; {
 
 /* Convert `mapped-when-managed' to `mappedWhenManaged'.
  */
-void Make_Resource_Name (s) register char *s; {
+void Make_Resource_Name (register char *s) {
     register char *p;
 
     for (p = s; *s; ) {
@@ -437,7 +437,7 @@ void Make_Resource_Name (s) register char *s; {
     *p = '\0';
 }
 
-Object Get_Resources (c, fun, freeit) WidgetClass c; void (*fun)(); {
+Object Get_Resources (WidgetClass c, void (*fun)(), int freeit) {
     XtResource *r;
     register XtResource *p;
     int nr;
diff --git a/lib/xwidgets/translation.c b/lib/xwidgets/translation.c
index b94107e..82ddf77 100644
--- a/lib/xwidgets/translation.c
+++ b/lib/xwidgets/translation.c
@@ -30,7 +30,7 @@
 
 #include "xt.h"
 
-XtTranslations Get_Translations (t) Object t; {
+XtTranslations Get_Translations (Object t) {
     register char *s;
     XtTranslations ret;
     Alloca_Begin;
@@ -42,19 +42,19 @@ XtTranslations Get_Translations (t) Object t; {
     return ret;
 }
 
-static Object P_Augment_Translations (w, t) Object w, t; {
+static Object P_Augment_Translations (Object w, Object t) {
     Check_Widget (w);
     XtAugmentTranslations (WIDGET(w)->widget, Get_Translations (t));
     return Void;
 }
 
-static Object P_Override_Translations (w, t) Object w, t; {
+static Object P_Override_Translations (Object w, Object t) {
     Check_Widget (w);
     XtOverrideTranslations (WIDGET(w)->widget, Get_Translations (t));
     return Void;
 }
 
-static Object P_Uninstall_Translations (w) Object w; {
+static Object P_Uninstall_Translations (Object w) {
     Check_Widget (w);
     XtUninstallTranslations (WIDGET(w)->widget);
     return Void;
@@ -63,18 +63,18 @@ static Object P_Uninstall_Translations (w) Object w; {
 /* Due to a bug in Xt these functions drop core when invoked with a
  * display not owned by Xt.
  */
-static Object P_Multi_Click_Time (d) Object d; {
+static Object P_Multi_Click_Time (Object d) {
     Check_Type (d, T_Display);
     return Make_Integer (XtGetMultiClickTime (DISPLAY(d)->dpy));
 }
 
-static Object P_Set_Multi_Click_Time (d, t) Object d, t; {
+static Object P_Set_Multi_Click_Time (Object d, Object t) {
     Check_Type (d, T_Display);
     XtSetMultiClickTime (DISPLAY(d)->dpy, Get_Integer (t));
     return Void;
 }
 
-elk_init_xt_translation () {
+void elk_init_xt_translation () {
     Define_Primitive (P_Augment_Translations,
                         "augment-translations",                  2, 2, EVAL);
     Define_Primitive (P_Override_Translations,
diff --git a/lib/xwidgets/widget.c b/lib/xwidgets/widget.c
index fc173fa..ee05649 100644
--- a/lib/xwidgets/widget.c
+++ b/lib/xwidgets/widget.c
@@ -40,7 +40,7 @@ Generic_Equal (Widget, WIDGET, widget)
 
 Generic_Print (Widget, "#[widget %lu]", POINTER(x))
 
-static Object Internal_Make_Widget (finalize, widget) Widget widget; {
+static Object Internal_Make_Widget (int finalize, Widget widget) {
     Object w;
 
     if (widget == 0)
@@ -60,33 +60,33 @@ static Object Internal_Make_Widget (finalize, widget) Widget widget; {
 }
 
 /* Backwards compatibility: */
-Object Make_Widget (widget) Widget widget; {
+Object Make_Widget (Widget widget) {
     return Internal_Make_Widget (1, widget);
 }
 
-Object Make_Widget_Foreign (widget) Widget widget; {
+Object Make_Widget_Foreign (Widget widget) {
     return Internal_Make_Widget (0, widget);
 }
 
-void Check_Widget (w) Object w; {
+void Check_Widget (Object w) {
     Check_Type (w, T_Widget);
     if (WIDGET(w)->free)
         Primitive_Error ("invalid widget: ~s", w);
 }
 
-void Check_Widget_Class (w, class) Object w; WidgetClass class; {
+void Check_Widget_Class (Object w, WidgetClass class) {
     Check_Widget (w);
     if (XtClass (WIDGET(w)->widget) != class)
         Primitive_Error ("widget not of expected class: ~s", w);
 }
 
-static Object P_Destroy_Widget (w) Object w; {
+static Object P_Destroy_Widget (Object w) {
     Check_Widget (w);
     XtDestroyWidget (WIDGET(w)->widget);
     return Void;
 }
 
-static Object P_Create_Shell (argc, argv) Object *argv; {
+static Object P_Create_Shell (int argc, Object *argv) {
     register char *sn = 0, *sc = 0;
     ArgList a;
     Object name, class, w, d, ret;
@@ -106,7 +106,7 @@ static Object P_Create_Shell (argc, argv) Object *argv; {
     return ret;
 }
 
-static Object P_Create_Widget (argc, argv) Object *argv; {
+static Object P_Create_Widget (int argc, Object *argv) {
     ArgList a;
     char *name = 0;
     Object x, class, parent, ret;
@@ -131,34 +131,34 @@ static Object P_Create_Widget (argc, argv) Object *argv; {
     return ret;
 }
 
-static Object P_Realize_Widget (w) Object w; {
+static Object P_Realize_Widget (Object w) {
     Check_Widget (w);
     XtRealizeWidget (WIDGET(w)->widget);
     return Void;
 }
 
-static Object P_Unrealize_Widget (w) Object w; {
+static Object P_Unrealize_Widget (Object w) {
     Check_Widget (w);
     XtUnrealizeWidget (WIDGET(w)->widget);
     return Void;
 }
 
-static Object P_Widget_Realizedp (w) Object w; {
+static Object P_Widget_Realizedp (Object w) {
     Check_Widget (w);
     return XtIsRealized (WIDGET(w)->widget) ? True : False;
 }
 
-static Object P_Widget_Display (w) Object w; {
+static Object P_Widget_Display (Object w) {
     Check_Widget (w);
     return Make_Display (0, XtDisplayOfObject (WIDGET(w)->widget));
 }
 
-static Object P_Widget_Parent (w) Object w; {
+static Object P_Widget_Parent (Object w) {
     Check_Widget (w);
     return Make_Widget_Foreign (XtParent (WIDGET(w)->widget));
 }
 
-static Object P_Widget_Name (w) Object w; {
+static Object P_Widget_Name (Object w) {
     char *s;
 
     Check_Widget (w);
@@ -166,19 +166,19 @@ static Object P_Widget_Name (w) Object w; {
     return Make_String (s, strlen (s));
 }
 
-static Object P_Widget_To_Window (w) Object w; {
+static Object P_Widget_To_Window (Object w) {
     Check_Widget (w);
     return Make_Window (0, XtDisplayOfObject (WIDGET(w)->widget),
         XtWindow (WIDGET(w)->widget));
 }
 
-static Object P_Widget_Compositep (w) Object w; {
+static Object P_Widget_Compositep (Object w) {
     Check_Widget (w);
     return XtIsComposite (WIDGET(w)->widget) ? True : False;
 }
 
-static Object Manage_Unmanage (children, f) Object children; void (*f)(); {
-    register i, n;
+static Object Manage_Unmanage (Object children, void (*f)()) {
+    register int i, n;
     Widget *buf;
     Object tail;
     Alloca_Begin;
@@ -198,60 +198,60 @@ static Object Manage_Unmanage (children, f) Object children; void (*f)(); {
     return Void;
 }
 
-static Object P_Manage_Children (children) Object children; {
+static Object P_Manage_Children (Object children) {
     return Manage_Unmanage (children, XtManageChildren);
 }
 
-static Object P_Unmanage_Children (children) Object children; {
+static Object P_Unmanage_Children (Object children) {
     return Manage_Unmanage (children, XtUnmanageChildren);
 }
 
-static Object P_Widget_Managedp (w) Object w; {
+static Object P_Widget_Managedp (Object w) {
     Check_Widget (w);
     return XtIsManaged (WIDGET(w)->widget) ? True : False;
 }
 
-static Object P_Widget_Class (w) Object w; {
+static Object P_Widget_Class (Object w) {
     Check_Widget (w);
     return Make_Widget_Class (XtClass (WIDGET(w)->widget));
 }
 
-static Object P_Widget_Superclass (w) Object w; {
+static Object P_Widget_Superclass (Object w) {
     Check_Widget (w);
     if (XtClass (WIDGET(w)->widget) == widgetClass)
         return Sym_None;
     return Make_Widget_Class (XtSuperclass (WIDGET(w)->widget));
 }
 
-static Object P_Widget_Subclassp (w, c) Object w, c; {
+static Object P_Widget_Subclassp (Object w, Object c) {
     Check_Widget (w);
     Check_Type (c, T_Class);
     return XtIsSubclass (WIDGET(w)->widget, CLASS(c)->wclass) ? True : False;
 }
 
-static Object P_Set_Mapped_When_Managed (w, m) Object w, m; {
+static Object P_Set_Mapped_When_Managed (Object w, Object m) {
     Check_Widget (w);
     Check_Type (m, T_Boolean);
     XtSetMappedWhenManaged (WIDGET(w)->widget, EQ(m, True));
     return Void;
 }
 
-static Object P_Map_Widget (w) Object w; {
+static Object P_Map_Widget (Object w) {
     Check_Widget (w);
     XtMapWidget (WIDGET(w)->widget);
     return Void;
 }
 
-static Object P_Unmap_Widget (w) Object w; {
+static Object P_Unmap_Widget (Object w) {
     Check_Widget (w);
     XtUnmapWidget (WIDGET(w)->widget);
     return Void;
 }
 
-static Object P_Set_Values (argc, argv) Object *argv; {
+static Object P_Set_Values (int argc, Object *argv) {
     ArgList a;
     Widget w;
-    register i, n = (argc-1)/2;
+    register int i, n = (argc-1)/2;
     Alloca_Begin;
 
     Check_Widget (argv[0]);
@@ -265,7 +265,7 @@ static Object P_Set_Values (argc, argv) Object *argv; {
     return Void;
 }
 
-static Object P_Get_Values (argc, argv) Object *argv; {
+static Object P_Get_Values (int argc, Object *argv) {
     Widget w;
 
     Check_Widget (argv[0]);
@@ -273,39 +273,37 @@ static Object P_Get_Values (argc, argv) Object *argv; {
     return Get_Values (w, argc-1, argv+1);
 }
 
-static Object P_Widget_Context (w) Object w; {
+static Object P_Widget_Context (Object w) {
     Check_Widget (w);
     return
         Make_Context_Foreign (XtWidgetToApplicationContext (WIDGET(w)->widget));
 }
 
-static Object P_Set_Sensitive (w, s) Object w, s; {
+static Object P_Set_Sensitive (Object w, Object s) {
     Check_Widget (w);
     Check_Type (s, T_Boolean);
     XtSetSensitive (WIDGET(w)->widget, EQ(s, True));
     return Void;
 }
 
-static Object P_Sensitivep (w) Object w; {
+static Object P_Sensitivep (Object w) {
     Check_Widget (w);
     return XtIsSensitive (WIDGET(w)->widget) ? True : False;
 }
 
-static Object P_Window_To_Widget (w) Object w; {
+static Object P_Window_To_Widget (Object w) {
     Check_Type (w, T_Window);
     return Make_Widget_Foreign (XtWindowToWidget (WINDOW(w)->dpy,
         WINDOW(w)->win));
 }
 
-static Object P_Name_To_Widget (root, name) Object root, name; {
-    register char *s;
-
+static Object P_Name_To_Widget (Object root, Object name) {
     Check_Widget (root);
     return Make_Widget_Foreign (XtNameToWidget (WIDGET(root)->widget,
         Get_Strsym (name)));
 }
 
-static Object P_Widget_Translate_Coordinates (w, x, y) Object w, x, y; {
+static Object P_Widget_Translate_Coordinates (Object w, Object x, Object y) {
     Position root_x, root_y;
 
     Check_Widget (w);
@@ -324,12 +322,12 @@ static Object P_Widget_Translate_Coordinates (w, x, y) Object w, x, y; {
 #include <X11/CompositeP.h>
 #undef XtIsComposite
 
-static Widget_Visit (root, func) Object *root; int (*func)(); {
+static int Widget_Visit (Object *root, int (*func)()) {
     Object obj;
     Widget w = WIDGET(*root)->widget;
 
     if (WIDGET(*root)->free == 0 && XtIsComposite (w)) {
-        int i;
+        unsigned int i;
         CompositeRec *comp = (CompositeRec *)w;
 
         for (i = 0; i < comp->composite.num_children; i++) {
@@ -338,15 +336,16 @@ static Widget_Visit (root, func) Object *root; int (*func)(); {
             if (TYPE(obj) == T_Widget)
                 func (&obj);
         }
-        while (w = XtParent (w)) {
+        while ((w = XtParent (w))) {
             obj = Find_Object (T_Widget, (GENERIC)0, Match_Xt_Obj, w);
             if (TYPE(obj) == T_Widget)
                 func (&obj);
         }
     }
+    return 0;
 }
 
-elk_init_xt_widget () {
+void elk_init_xt_widget () {
     T_Widget = Define_Type (0, "widget", NOFUNC, sizeof (struct S_Widget),
         Widget_Equal, Widget_Equal, Widget_Print, Widget_Visit);
     Define_Primitive (P_Widgetp,           "widget?",           1, 1, EVAL);
diff --git a/lib/xwidgets/xaw/grip.d b/lib/xwidgets/xaw/grip.d
index 3916408..3aea3ca 100644
--- a/lib/xwidgets/xaw/grip.d
+++ b/lib/xwidgets/xaw/grip.d
@@ -35,7 +35,7 @@
 
 (c->scheme 'callback:grip-callback
 "   Object args, ret, t;
-    register i;
+    register unsigned int i;
     GripCallData p = (GripCallData)x;
     GC_Node3;
 
diff --git a/lib/xwidgets/xaw/init.c b/lib/xwidgets/xaw/init.c
index 60336d0..7ec06be 100644
--- a/lib/xwidgets/xaw/init.c
+++ b/lib/xwidgets/xaw/init.c
@@ -30,6 +30,6 @@
 
 #include "scheme.h"
 
-elk_init_xaw_init () {
+void elk_init_xaw_init () {
     P_Provide (Intern ("xaw-widgets.so"));
 }
diff --git a/lib/xwidgets/xaw/list.d b/lib/xwidgets/xaw/list.d
index fbb4ffd..03088f9 100644
--- a/lib/xwidgets/xaw/list.d
+++ b/lib/xwidgets/xaw/list.d
@@ -31,8 +31,8 @@
 
 (prolog
 "
-static char **Get_List (x) Object x; {
-    register i, n;
+static char **Get_List (Object x) {
+    register int i, n;
     register char *s, **l;
     Alloca_Begin;
 
diff --git a/lib/xwidgets/xaw/stripchart.d b/lib/xwidgets/xaw/stripchart.d
index 9f3abad..13461d6 100644
--- a/lib/xwidgets/xaw/stripchart.d
+++ b/lib/xwidgets/xaw/stripchart.d
@@ -31,8 +31,7 @@
 
 (prolog
 
-"static void Get_Value (w, client_data, value) Widget w;
-	XtPointer client_data; XtPointer value; {
+"static void Get_Value (Widget w, XtPointer client_data, XtPointer value) {
     Object ret;
 
     ret = Funcall (Get_Function ((int)client_data), Null, 0);
diff --git a/lib/xwidgets/xterror.c b/lib/xwidgets/xterror.c
index 84eb145..1c05ee2 100644
--- a/lib/xwidgets/xterror.c
+++ b/lib/xwidgets/xterror.c
@@ -32,7 +32,7 @@
 
 static Object V_Xt_Warning_Handler;
 
-void Xt_Warning (msg) char *msg; {
+void Xt_Warning (char *msg) {
     Object args, fun;
 
     args = Cons (Make_String (msg, strlen (msg)), Null);
@@ -43,7 +43,7 @@ void Xt_Warning (msg) char *msg; {
     (void)P_Newline (0, (Object *)0);
 }
 
-elk_init_xt_error () {
+void elk_init_xt_error () {
     Define_Variable (&V_Xt_Warning_Handler, "xt-warning-handler", Null);
     XtSetWarningHandler (Xt_Warning);
 }
diff --git a/lib/xwidgets/xtinit.c b/lib/xwidgets/xtinit.c
index 51fa874..078dfac 100644
--- a/lib/xwidgets/xtinit.c
+++ b/lib/xwidgets/xtinit.c
@@ -58,10 +58,10 @@ extern WidgetClass vendorShellWidgetClass;
  * it isn't removed by the optimizer.
  */
 
-static dummy (w) WidgetClass w; {
+static void dummy (WidgetClass w) {
 }
 
-elk_init_xt_init () {
+void elk_init_xt_init () {
     extern WidgetClass vendorShellWidgetClass;
 
     dummy(vendorShellWidgetClass);
diff --git a/lib/xwidgets/xtobjects.c b/lib/xwidgets/xtobjects.c
index 6e5db9b..2e6a688 100644
--- a/lib/xwidgets/xtobjects.c
+++ b/lib/xwidgets/xtobjects.c
@@ -32,8 +32,8 @@
 
 #include "xt.h"
 
-Match_Xt_Obj (x, v) Object x; va_list v; {
-    register type = TYPE(x);
+int Match_Xt_Obj (Object x, va_list v) {
+    register int type = TYPE(x);
 
     if (type == T_Context) {
         return va_arg (v, XtAppContext) == CONTEXT(x)->context;