diff --git a/src/string.c b/src/string.c
index 40f7081b0..cd1a01cbc 100644
--- a/src/string.c
+++ b/src/string.c
@@ -332,6 +332,7 @@ search_nonascii(const char *p, const char *e)
   case 2:  if (NOASCII(*p)) return p; ++p;
   case 1:  if (NOASCII(*p)) return p; ++p;
            if (NOASCII(*p)) return p;
+  case 0:  break;
   }
   return e;
 }