diff --git a/components/script/lib.rs b/components/script/lib.rs
index 144644438e5..642efd54650 100644
--- a/components/script/lib.rs
+++ b/components/script/lib.rs
@@ -90,6 +90,6 @@ mod webdriver_handlers;
 #[allow(unsafe_code)]
 pub fn init() {
     unsafe {
-        js::jsapi::JS_Init();
+        assert_eq!(js::jsapi::JS_Init(), 1);
     }
 }