diff --git a/legacy/embryo/src/bin/embryo_cc_sc.h b/legacy/embryo/src/bin/embryo_cc_sc.h
index 023485a324..5b3a9e5d70 100644
--- a/legacy/embryo/src/bin/embryo_cc_sc.h
+++ b/legacy/embryo/src/bin/embryo_cc_sc.h
@@ -438,7 +438,6 @@ typedef struct __s_stringpair
 #endif
 
 /* function prototypes in SC1.C */
-void        set_extension(char *filename, char *extension, int force);
 symbol     *fetchfunc(char *name, int tag);
 char       *operator_symname(char *symname, char *opername, int tag1,
 				     int tag2, int numtags, int resulttag);
diff --git a/legacy/embryo/src/bin/embryo_cc_sc1.c b/legacy/embryo/src/bin/embryo_cc_sc1.c
index 111e16f15f..7afd3f1873 100644
--- a/legacy/embryo/src/bin/embryo_cc_sc1.c
+++ b/legacy/embryo/src/bin/embryo_cc_sc1.c
@@ -592,40 +592,6 @@ initglobals(void)
 
 }
 
-/* set_extension
- * Set the default extension, or force an extension. To erase the
- * extension of a filename, set "extension" to an empty string.
- */
-SC_FUNC void
-set_extension(char *filename, char *extension, int force)
-{
-   char               *ptr;
-
-   ptr = strrchr(filename, '.');
-#if 0
-   if (ptr != NULL)
-     {
-	/* ignore extension on a directory or at the start of the filename */
-	if (strchr(ptr, DIRSEP_CHAR) != NULL || ptr == filename
-	    || *(ptr - 1) == DIRSEP_CHAR)
-	   ptr = NULL;
-     }				/* if */
-   if (force && ptr != NULL)
-      *ptr = '\0';		/* set zero terminator at the position of the period */
-   if (force || ptr == NULL)
-      strcat(filename, extension);
-#else
-   if (!ptr)
-     {
-	strcat(filename, extension);
-     }
-   else
-     {
-	strncpy(ptr, extension, strlen(extension));
-     }
-#endif
-}
-
 static void
 parseoptions(int argc, char **argv, char *iname, char *oname,
              char *pname, char *rname)