diff --git a/scripts/fix-bison.pl b/scripts/fix-bison.pl
index 2327a7ae..f4cad096 100755
--- a/scripts/fix-bison.pl
+++ b/scripts/fix-bison.pl
@@ -98,6 +98,8 @@ ($)
     my $line=$. +$line_offset;
     s/^(\#line) \d+ (.*\.c)/$1 $line $2/;
 
+    # Remove all mention of unused var yynerrs
+    s%^(\s*)(.*yynerrs.*)%$1/* $2 */%;
     print OUT;
   }
 }