diff --git a/bin/hilfe b/bin/hilfe
index 2d3978f08bc73ff98d6ae1898e76be5dcb5713ce..d5b0483dc286121ee6bd7c93de93b8ff036edb34 100755
--- a/bin/hilfe
+++ b/bin/hilfe
@@ -201,6 +201,12 @@ int do_parse()
     if(!first_word)
     {
       int d;
+      if(!strlen(input) && pos)
+      {
+	werror("Error in optimizer.\n");
+	exit(1);
+      }
+
       d=input[pos];
       if(d==' ' && !pos)
       {