diff --git a/utils.c b/utils.c
index afc88fa..3d9911a 100644
--- a/utils.c
+++ b/utils.c
@@ -54,7 +54,7 @@ file_get_extension(const char* path)
 bool
 file_valid_extension(zathura_t* zathura, const char* path)
 {
-  if (path == NULL) {
+  if (zathura == NULL || path == NULL) {
     return false;
   }