diff --git a/src/openvpn/buffer.c b/src/openvpn/buffer.c
index 0b94a52..2ad3461 100644
--- a/src/openvpn/buffer.c
+++ b/src/openvpn/buffer.c
@@ -822,7 +822,7 @@
 buf_string_match_head_str(const struct buffer *src, const char *match)
 {
     const size_t size = strlen(match);
-    if (size < 0 || size > src->len)
+    if (size > src->len)
     {
         return false;
     }