diff --git a/inc/core.php b/inc/core.php
index e09a7a2..df07470 100644
--- a/inc/core.php
+++ b/inc/core.php
@@ -433,7 +433,7 @@ function sha1Exists($sha1)
     $handle = fopen(ROOT.DS.'data'.DS.'sha1.csv', "r");
     if ($handle) {
         while (($line = fgets($handle)) !== false) {
-            if(substr($line,0,40)==$sha1) return trim(substr($line,41));
+            if(substr($line,0,40)===$sha1) return trim(substr($line,41));
         }
 
         fclose($handle);
@@ -703,4 +703,4 @@ function executeUploadPermission()
         http_response_code(403);
         exit(json_encode(array('status'=>'err','reason'=> 'Access denied')));
     }
-}
\ No newline at end of file
+}