diff --git a/scm/troff.scm b/scm/troff.scm
index 06f1922..d21b624 100644
--- a/scm/troff.scm
+++ b/scm/troff.scm
@@ -273,9 +273,9 @@
 		   (loop (read-line))))))
     (cond
       ((string=? delim "##")
-	(with-output-to-stream '[##]
+	(with-output-to-stream 'hash-hash
 	  (copy-exec ".##\n" "inline Scheme execution"))
-	(let ((p (open-input-string (stream->string '[##]))))
+	(let ((p (open-input-string (stream->string 'hash-hash))))
 	  (copy-apply (lambda () (read p)) \##-eval)))
       ((string=? delim ">>")
 	(copy-exec ".>>\n" "transparent output"))
diff --git a/src/error.c b/src/error.c
index 7e8318e..2745d00 100644
--- a/src/error.c
+++ b/src/error.c
@@ -37,10 +37,7 @@ void fatal_error(char *fmt, ...) {
     exit(1);
 }
 
-static char *strerr(void) {
-    extern int sys_nerr;
-    extern char *sys_errlist[];
-
+static const char *strerr(void) {
     return errno > 0 && errno < sys_nerr ?
 	sys_errlist[errno] : "unknown error";
 }
diff --git a/src/error.h b/src/error.h
index 372a637..36c6991 100644
--- a/src/error.h
+++ b/src/error.h
@@ -12,9 +12,5 @@ void read_error(char *) NORETURN;
 void write_error(char *) NORETURN;
 void open_error(char *) NORETURN;
 
-/* Redefined to add NORETURN
- */
-extern Primitive_Error() NORETURN;
-
 char *printable_string(char *, int);
 char *printable_char(char);
diff --git a/src/expr.c b/src/expr.c
index 3743531..5da7344 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -170,7 +170,7 @@ err:        *p = 0;
 	    assert(0);
 	}
     }
-    if (!finite(acc)) {
+    if (!isfinite(acc)) {
 	warn("expression evaluates to infinity"); goto err;
     }
     return acc;
diff --git a/src/unroff.c b/src/unroff.c
index dce5c63..50f1d17 100644
--- a/src/unroff.c
+++ b/src/unroff.c
@@ -154,7 +154,8 @@ int main(int ac, char **av) {
 	directory = DEFAULT_DIR;
     if ((format = getenv(DEFAULT_FORMAT_ENV)) == 0)
 	format = DEFAULT_FORMAT;
-    eav = safe_malloc((ac+1+2) * sizeof(char *));    /* ac + -p xxx + 0-ptr */
+    /* av[0] "-g", "-p", "xxx", av[1...] NULL */
+    eav = safe_malloc((ac+3+1) * sizeof(char *));
     eav[0] = av[0];
     opterr = 0;
     while ((c = getopt(ac, av, "h:gm:f:tC")) != EOF) {
@@ -180,6 +181,7 @@ int main(int ac, char **av) {
 	    return 1;
 	}
     }
+    eav[eac++] = "-g";  /* We need symbols to be case-sensitive. */
     /* Set the Elk load-path to $(directory)/elk, so that a minimal,
      * self-contained Elk runtime environment can be shipped with
      * binary distributions.  Sites with a full Elk can symlink
diff --git a/src/unroff.h b/src/unroff.h
index 40e6611..82d0220 100644
--- a/src/unroff.h
+++ b/src/unroff.h
@@ -26,18 +26,9 @@ extern long strtol(const char *s, char **endp, int base);
 extern double strtod(const char *s, char **endp);
 extern int pclose(FILE *);
 extern int system(const char *);
-#ifndef tolower
-extern int tolower(int);
-#endif
-
-/* Prototypes for IEEE FP functions that may be missing:
- */
-#ifndef finite
-extern int finite(double);
-#endif
 
 
-#include "scheme.h"
+#include <elk/scheme.h>
 
 /* Prototypes that were missing from "scheme.h" in some Elk releases:
  */