diff --git a/components/script/script_thread.rs b/components/script/script_thread.rs
index 9e20b09ef20..b3bd5b1c396 100644
--- a/components/script/script_thread.rs
+++ b/components/script/script_thread.rs
@@ -809,11 +809,13 @@ impl ScriptThread {
 
     pub fn mark_document_with_no_blocked_loads(doc: &Document) {
         SCRIPT_THREAD_ROOT.with(|root| {
-            let script_thread = unsafe { &*root.get().unwrap() };
-            script_thread
-                .docs_with_no_blocking_loads
-                .borrow_mut()
-                .insert(Dom::from_ref(doc));
+            unsafe {
+            if let Some(script_thread) = root.get() {
+                (*script_thread)
+                    .docs_with_no_blocking_loads
+                    .borrow_mut()
+                    .insert(Dom::from_ref(doc));
+            }}
         })
     }