diff --git a/src/io.c b/src/io.c
index 8ce47af..1efc662 100644
--- a/src/io.c
+++ b/src/io.c
@@ -190,11 +190,7 @@ Object General_File_Operation (Object s, register int op) {
             return s;
         }
         Alloca (r, char*, strlen (dir) + 1 + strlen (p) + 1);
-#ifdef WIN32
-        sprintf (r, "%s\\%s", dir, p);
-#else
-        sprintf (r, "%s/%s", dir, p);
-#endif
+        sprintf (r, "%s" SEPARATOR_STRING "%s", dir, p);
         ret = Make_String (r, strlen (r));
         Alloca_End;
         return ret;
@@ -241,11 +237,7 @@ Object Open_File (char *name, int flags, int err) {
     p = Internal_Tilde_Expand (name, &dir);
     if (p) {
         Alloca (name, char*, strlen (dir) + 1 + strlen (p) + 1);
-#ifdef WIN32
-        sprintf (name, "%s\\%s", dir, p);
-#else
-        sprintf (name, "%s/%s", dir, p);
-#endif
+        sprintf (name, "%s" SEPARATOR_STRING "%s", dir, p);
     }
     if (!err && stat (name, &st) == -1 &&
             (errno == ENOENT || errno == ENOTDIR)) {
@@ -300,13 +292,8 @@ Object General_Open_File (Object name, int flags, Object path) {
                 Alloca (buf, char*, blen);
             }
             memcpy (buf, STRING(pref)->data, plen);
-#ifdef WIN32
-            if (buf[plen-1] != '\\')
-                buf[plen++] = '\\';
-#else
-            if (buf[plen-1] != '/')
-                buf[plen++] = '/';
-#endif
+            if (buf[plen-1] != SEPARATOR_CHAR)
+                buf[plen++] = SEPARATOR_CHAR;
             memcpy (buf+plen, fn, len);
             buf[len+plen] = '\0';
             port = Open_File (buf, flags, 0);
diff --git a/src/libelk.c b/src/libelk.c
index 4a479a0..9f6ad3d 100644
--- a/src/libelk.c
+++ b/src/libelk.c
@@ -309,11 +309,7 @@ void Elk_Init (int ac, char **av, int init_objects, char *toplevel) {
      */
     Set_Error_Tag ("scheme-init");
     initfile = Safe_Malloc (strlen (Scm_Dir) + 1 + sizeof (INITFILE) + 1);
-#ifdef WIN32
-    sprintf (initfile, "%s\\%s", Scm_Dir, INITFILE);
-#else
-    sprintf (initfile, "%s/%s", Scm_Dir, INITFILE);
-#endif
+    sprintf (initfile, "%s" SEPARATOR_STRING "%s", Scm_Dir, INITFILE);
     if (stat (initfile, &st) == -1 && errno == ENOENT)
         file = Make_String (INITFILE, sizeof(INITFILE)-1);
     else
diff --git a/src/loadlib.c b/src/loadlib.c
index 47c50f5..771ba68 100644
--- a/src/loadlib.c
+++ b/src/loadlib.c
@@ -197,21 +197,21 @@ static void Load_Lib (Object libs) {
         /* Our line starts with dlname='... */
         if (strncmp (buffer, "dlname", 6))
             continue;
-        dlname = index (buffer, '\'');
+        dlname = strchr (buffer, '\'');
         if (dlname == NULL)
             continue;
         dlname++;
-        eol = rindex (buffer, '\'');
+        eol = strrchr (buffer, '\'');
         if (eol == NULL || eol == dlname)
             continue;
         *eol = '\0';
         path = strdup (STRING(PORT(port)->name)->data);
-        eol = rindex (path, '/');
+        eol = strrchr (path, SEPARATOR_CHAR);
         if (eol == NULL)
             eol = path;
         *eol = '\0';
         lib = malloc (strlen (path) + 1 + strlen (dlname) + 1);
-        sprintf (lib, "%s/%s", path, dlname);
+        sprintf (lib, "%s" SEPARATOR_STRING "%s", path, dlname);
         free (path);
         break;
     }