diff --git a/dom/base/nsJSEnvironment.cpp b/dom/base/nsJSEnvironment.cpp
index 265f4af2176c..9b6f53cc700b 100644
--- a/dom/base/nsJSEnvironment.cpp
+++ b/dom/base/nsJSEnvironment.cpp
@@ -2186,11 +2186,15 @@ DOMGCSliceCallback(JSContext* aCx, JS::GCProgress aProgress, const JS::GCDescrip
       }
 
       if (sPostGCEventsToConsole) {
-        nsString gcstats;
+        NS_NAMED_LITERAL_STRING(kFmt, "[%s] ");
+        nsString prefix, gcstats;
         gcstats.Adopt(aDesc.formatSliceMessage(aCx));
+        prefix.Adopt(nsTextFormatter::smprintf(kFmt.get(),
+                                               ProcessNameForCollectorLog()));
+        nsString msg = prefix + gcstats;
         nsCOMPtr<nsIConsoleService> cs = do_GetService(NS_CONSOLESERVICE_CONTRACTID);
         if (cs) {
-          cs->LogStringMessage(gcstats.get());
+          cs->LogStringMessage(msg.get());
         }
       }