diff --git a/ext/standard/file.c b/ext/standard/file.c
index db783325eee..38d2a1e34ff 100644
--- a/ext/standard/file.c
+++ b/ext/standard/file.c
@@ -614,6 +614,7 @@ PHP_FUNCTION(file_put_contents)
 
 	if (flags & LOCK_EX && (!php_stream_supports_lock(stream) || php_stream_lock(stream, LOCK_EX))) {
 		php_stream_close(stream);
+		php_error_docref(NULL TSRMLS_CC, E_WARNING, "Exclusive locks are not supported for this stream");
 		RETURN_FALSE;
 	}