diff --git a/src/error.c b/src/error.c
index b027f8d6c813fb72c3760632e5d00fd62176b88d..c99d9a92438b5f2dd98ab461cd9383521b112a06 100644
--- a/src/error.c
+++ b/src/error.c
@@ -91,7 +91,7 @@ void va_error(char *fmt, va_list args)
     abort();
   }
 
-  if(strlen(buf) >= sizeof(buf))
+  if((long)strlen(buf) >= (long)sizeof(buf))
     fatal("Buffer overflow in error()\n");
   
   push_string(make_shared_string(buf));
diff --git a/src/gc.c b/src/gc.c
index e2ca81baa8b1d5adfc25b41a5a901cebb1c25c5c..8fa6e26bd59dbb7e3dd26186b2476e1cd077dab5 100644
--- a/src/gc.c
+++ b/src/gc.c
@@ -167,7 +167,7 @@ static INT32 hashprimes[] =
   2147483647,/* ~ 2^31 = 2147483648 */
 };
 
-void do_gc()
+void do_gc(void)
 {
   double tmp;
   INT32 tmp2;