--- a/tools/profiler/gecko/ProfileGatherer.cpp
+++ b/tools/profiler/gecko/ProfileGatherer.cpp
@@ -42,17 +42,19 @@ ProfileGatherer::GatheredOOPProfile(cons
     // If we're not actively gathering, then we don't actually
     // care that we gathered a profile here. This can happen for
     // processes that exit while profiling.
     return;
   }
 
   MOZ_RELEASE_ASSERT(mWriter.isSome(), "Should always have a writer if mGathering is true");
 
-  mWriter->Splice(PromiseFlatCString(aProfile).get());
+  if (!aProfile.IsEmpty()) {
+    mWriter->Splice(PromiseFlatCString(aProfile).get());
+  }
 
   mPendingProfiles--;
 
   if (mPendingProfiles == 0) {
     // We've got all of the async profiles now. Let's
     // finish off the profile and resolve the Promise.
     Finish();
   }