diff --git a/js/src/jit/AsmJS.cpp b/js/src/jit/AsmJS.cpp
index 2a17102b3bdd..41ce90d5d6fa 100644
--- a/js/src/jit/AsmJS.cpp
+++ b/js/src/jit/AsmJS.cpp
@@ -1276,6 +1276,8 @@ class MOZ_STACK_CLASS ModuleCompiler
     }
 
     bool failName(ParseNode *pn, const char *fmt, PropertyName *name) {
+        // This function is invoked without the caller properly rooting its locals.
+        gc::AutoSuppressGC suppress(name->runtimeFromMainThread());
         JSAutoByteString bytes;
         if (AtomToPrintableString(cx_, name, &bytes))
             failf(pn, fmt, bytes.ptr());
diff --git a/js/src/jsgc.cpp b/js/src/jsgc.cpp
index 26dd00fe2a7b..1cd354ca73e1 100644
--- a/js/src/jsgc.cpp
+++ b/js/src/jsgc.cpp
@@ -5140,6 +5140,12 @@ AutoMaybeTouchDeadZones::~AutoMaybeTouchDeadZones()
     runtime->gcManipulatingDeadZones = manipulatingDeadZones;
 }
 
+AutoSuppressGC::AutoSuppressGC(JSRuntime *rt)
+  : suppressGC_(rt->mainThread.suppressGC)
+{
+    suppressGC_++;
+}
+
 AutoSuppressGC::AutoSuppressGC(JSContext *cx)
   : suppressGC_(cx->runtime()->mainThread.suppressGC)
 {
diff --git a/js/src/jsgc.h b/js/src/jsgc.h
index 220d7bc92ceb..0c66cd98b18f 100644
--- a/js/src/jsgc.h
+++ b/js/src/jsgc.h
@@ -1400,6 +1400,7 @@ class AutoSuppressGC
     int32_t &suppressGC_;
 
   public:
+    AutoSuppressGC(JSRuntime *rt);
     AutoSuppressGC(JSContext *cx);
     AutoSuppressGC(JSCompartment *comp);