diff --git a/dom/ipc/ContentChild.cpp b/dom/ipc/ContentChild.cpp
index 403cb3c9b865..c5c576517996 100644
--- a/dom/ipc/ContentChild.cpp
+++ b/dom/ipc/ContentChild.cpp
@@ -2663,6 +2663,7 @@ mozilla::ipc::IPCResult ContentChild::RecvRemoteType(
 
   // Turn off Spectre mitigations in isolated web content processes.
   if (StaticPrefs::javascript_options_spectre_disable_for_isolated_content() &&
+      StaticPrefs::browser_opaqueResponseBlocking() &&
       (remoteTypePrefix == FISSION_WEB_REMOTE_TYPE ||
        remoteTypePrefix == SERVICEWORKER_REMOTE_TYPE ||
        remoteTypePrefix == WITH_COOP_COEP_REMOTE_TYPE ||