diff --git a/utils/args.c b/utils/args.c
index 67b550c9..e04834d1 100644
--- a/utils/args.c
+++ b/utils/args.c
@@ -56,7 +56,7 @@ char *
 ArgStr(pargc, pargv, argType)
     int *pargc;
     char ***pargv;
-    char *argType;	/* For error messages: what the following string is
+    const char *argType;/* For error messages: what the following string is
 			 * supposed to be interpreted as.
 			 */
 {
diff --git a/utils/utils.h b/utils/utils.h
index d27a9fe4..b51cb12d 100644
--- a/utils/utils.h
+++ b/utils/utils.h
@@ -52,7 +52,7 @@ extern FILE *PaOpen(char *, char *, char *, char *, char *, char **);
 extern FILE *PaLockOpen(char *, char *, char *, char *, char *, char **, bool *, int *);
 extern char *StrDup(char **, const char *);
 extern bool Match(const char *pattern, const char *string);
-extern char *ArgStr();
+extern char *ArgStr(int *pargc, char ***pargv, const char *argType);
 extern bool StrIsWhite(const char *, bool);
 extern bool StrIsInt(const char *);
 extern bool StrIsNumeric(const char *);