diff --git a/caps/nsJSPrincipals.cpp b/caps/nsJSPrincipals.cpp
index dadb3f84d4ac..047b9350b1ab 100644
--- a/caps/nsJSPrincipals.cpp
+++ b/caps/nsJSPrincipals.cpp
@@ -386,6 +386,7 @@ bool nsJSPrincipals::write(JSContext* aCx, JSStructuredCloneWriter* aWriter) {
 }
 
 bool nsJSPrincipals::isSystemOrAddonPrincipal() {
+  JS::AutoSuppressGCAnalysis suppress;
   return this->IsSystemPrincipal() ||
          this->GetIsAddonOrExpandedAddonPrincipal();
 }