diff --git a/src/IncludeInterceptor.php b/src/IncludeInterceptor.php
index 3ebd627..d0adb5d 100644
--- a/src/IncludeInterceptor.php
+++ b/src/IncludeInterceptor.php
@@ -249,7 +249,7 @@ public function stream_lock($operation)
     {
         assert(is_resource($this->fp));
 
-        return flock($this->fp, LOCK_SH);
+        return true;
     }
 
     public function stream_metadata($path, $option, $value)