diff --git a/js/src/gc/GCRuntime.h b/js/src/gc/GCRuntime.h
index 0e6969055a..b1b4ffcba4 100644
--- a/js/src/gc/GCRuntime.h
+++ b/js/src/gc/GCRuntime.h
@@ -977,7 +977,6 @@ class GCRuntime
     void releaseRelocatedArenasWithoutUnlocking(Arena* arenaList, const AutoLockGC& lock);
     void finishCollection(JS::gcreason::Reason reason);
 
-    void computeNonIncrementalMarkingForValidation(AutoLockForExclusiveAccess& lock);
     void validateIncrementalMarking();
     void finishMarkingValidation();
 
diff --git a/js/src/jsgc.cpp b/js/src/jsgc.cpp
index cf2981dbc1..5082d03713 100644
--- a/js/src/jsgc.cpp
+++ b/js/src/jsgc.cpp
@@ -3885,11 +3885,6 @@ GCRuntime::markAllGrayReferences(gcstats::Phase phase)
     markGrayReferences<GCZonesIter, GCCompartmentsIter>(phase);
 }
 
-void
-GCRuntime::computeNonIncrementalMarkingForValidation(AutoLockForExclusiveAccess& lock)
-{
-}
-
 void
 GCRuntime::validateIncrementalMarking()
 {
@@ -4761,8 +4756,6 @@ GCRuntime::beginSweepPhase(bool destroyingRuntime, AutoLockForExclusiveAccess& l
 
     releaseHeldRelocatedArenas();
 
-    computeNonIncrementalMarkingForValidation(lock);
-
     gcstats::AutoPhase ap(stats, gcstats::PHASE_SWEEP);
 
     sweepOnBackgroundThread =