--- a/bc/execute.c
+++ b/bc/execute.c
@@ -595,7 +595,7 @@ input_char (void)
   if (in_ch == '.' || in_ch == '+' || in_ch == '-')
     return (in_ch);
   if (in_ch <= ' ')
-    return (' ');
+    return (':');
   
   return (':');
 }