diff --git a/src/mod/applications/mod_http_cache/aws.c b/src/mod/applications/mod_http_cache/aws.c
index cc02b4e5b5..264756eda7 100644
--- a/src/mod/applications/mod_http_cache/aws.c
+++ b/src/mod/applications/mod_http_cache/aws.c
@@ -47,7 +47,7 @@
  */
 static char *hmac256(char* buffer, unsigned int buffer_length, const char* key, unsigned int key_length, const char* message)
 {
-	if (zstr(key) || zstr(message) || buffer_length < SHA256_DIGEST_LENGTH) {
+	if (!key || zstr(message) || buffer_length < SHA256_DIGEST_LENGTH) {
 		return NULL;
 	}