diff --git a/src/Context/JsonContext.php b/src/Context/JsonContext.php
index 99630567..d835fc91 100644
--- a/src/Context/JsonContext.php
+++ b/src/Context/JsonContext.php
@@ -323,7 +323,7 @@ public function theJsonShouldBeValidAccordingToTheSchema($filename)
             $this->getJson(),
             new JsonSchema(
                 file_get_contents($filename),
-                'file://' . realpath($filename)
+                'file://' . str_replace(DIRECTORY_SEPARATOR, '/', realpath($filename))
             )
         );
     }