diff --git a/src/gpu/mtl/GrMtlGpu.h b/src/gpu/mtl/GrMtlGpu.h
index 607f704..cc13645 100644
--- a/src/gpu/mtl/GrMtlGpu.h
+++ b/src/gpu/mtl/GrMtlGpu.h
@@ -108,7 +108,7 @@
     sk_sp<GrSemaphore> wrapBackendSemaphore(const GrBackendSemaphore& semaphore,
                                             GrResourceProvider::SemaphoreWrapType wrapType,
                                             GrWrapOwnership ownership) override { return nullptr; }
-    void insertSemaphore(sk_sp<GrSemaphore> semaphore, bool flush) override {}
+    void insertSemaphore(sk_sp<GrSemaphore> semaphore) override {}
     void waitSemaphore(sk_sp<GrSemaphore> semaphore) override {}
     sk_sp<GrSemaphore> prepareTextureForCrossContextUsage(GrTexture*) override { return nullptr; }