diff --git a/gfx/layers/ipc/CompositorBridgeParent.cpp b/gfx/layers/ipc/CompositorBridgeParent.cpp
index 4a337f5729d2..48c9853e660f 100644
--- a/gfx/layers/ipc/CompositorBridgeParent.cpp
+++ b/gfx/layers/ipc/CompositorBridgeParent.cpp
@@ -1308,10 +1308,10 @@ CompositorBridgeParent::RecvGetFrameUniformity(FrameUniformityData* aOutData)
 }
 
 void
-CompositorBridgeParent::FlushApzRepaints(const LayerTransactionParent* aLayerTree)
+CompositorBridgeParent::FlushApzRepaints(const uint64_t& aLayersId)
 {
   MOZ_ASSERT(mApzcTreeManager);
-  uint64_t layersId = aLayerTree->GetId();
+  uint64_t layersId = aLayersId;
   if (layersId == 0) {
     // The request is coming from the parent-process layer tree, so we should
     // use the compositor's root layer tree id.
diff --git a/gfx/layers/ipc/CompositorBridgeParent.h b/gfx/layers/ipc/CompositorBridgeParent.h
index 8bd607a72e0d..d15d23d2b145 100644
--- a/gfx/layers/ipc/CompositorBridgeParent.h
+++ b/gfx/layers/ipc/CompositorBridgeParent.h
@@ -108,7 +108,7 @@ public:
   virtual void LeaveTestMode(LayerTransactionParent* aLayerTree) { }
   virtual void ApplyAsyncProperties(LayerTransactionParent* aLayerTree) = 0;
   virtual CompositorAnimationStorage* GetAnimationStorage(const uint64_t& aId) { return nullptr; }
-  virtual void FlushApzRepaints(const LayerTransactionParent* aLayerTree) = 0;
+  virtual void FlushApzRepaints(const uint64_t& aLayersId) = 0;
   virtual void GetAPZTestData(const LayerTransactionParent* aLayerTree,
                               APZTestData* aOutData) { }
   virtual void SetConfirmedTargetAPZC(const LayerTransactionParent* aLayerTree,
@@ -231,7 +231,7 @@ public:
   virtual void ApplyAsyncProperties(LayerTransactionParent* aLayerTree)
                override;
   virtual CompositorAnimationStorage* GetAnimationStorage(const uint64_t& aId) override;
-  virtual void FlushApzRepaints(const LayerTransactionParent* aLayerTree) override;
+  virtual void FlushApzRepaints(const uint64_t& aLayersId) override;
   virtual void GetAPZTestData(const LayerTransactionParent* aLayerTree,
                               APZTestData* aOutData) override;
   virtual void SetConfirmedTargetAPZC(const LayerTransactionParent* aLayerTree,
diff --git a/gfx/layers/ipc/CrossProcessCompositorBridgeParent.cpp b/gfx/layers/ipc/CrossProcessCompositorBridgeParent.cpp
index b85cb97d5ab4..d00876eb8951 100644
--- a/gfx/layers/ipc/CrossProcessCompositorBridgeParent.cpp
+++ b/gfx/layers/ipc/CrossProcessCompositorBridgeParent.cpp
@@ -422,18 +422,17 @@ CrossProcessCompositorBridgeParent::GetAnimationStorage(
 }
 
 void
-CrossProcessCompositorBridgeParent::FlushApzRepaints(const LayerTransactionParent* aLayerTree)
+CrossProcessCompositorBridgeParent::FlushApzRepaints(const uint64_t& aLayersId)
 {
-  uint64_t id = aLayerTree->GetId();
-  MOZ_ASSERT(id != 0);
+  MOZ_ASSERT(aLayersId != 0);
   const CompositorBridgeParent::LayerTreeState* state =
-    CompositorBridgeParent::GetIndirectShadowTree(id);
+    CompositorBridgeParent::GetIndirectShadowTree(aLayersId);
   if (!state) {
     return;
   }
 
   MOZ_ASSERT(state->mParent);
-  state->mParent->FlushApzRepaints(aLayerTree);
+  state->mParent->FlushApzRepaints(aLayersId);
 }
 
 void
diff --git a/gfx/layers/ipc/CrossProcessCompositorBridgeParent.h b/gfx/layers/ipc/CrossProcessCompositorBridgeParent.h
index 4e9bc3508b1b..c5f4a3f333e7 100644
--- a/gfx/layers/ipc/CrossProcessCompositorBridgeParent.h
+++ b/gfx/layers/ipc/CrossProcessCompositorBridgeParent.h
@@ -104,7 +104,7 @@ public:
                override;
   virtual CompositorAnimationStorage*
     GetAnimationStorage(const uint64_t& aId) override;
-  virtual void FlushApzRepaints(const LayerTransactionParent* aLayerTree) override;
+  virtual void FlushApzRepaints(const uint64_t& aLayersId) override;
   virtual void GetAPZTestData(const LayerTransactionParent* aLayerTree,
                               APZTestData* aOutData) override;
   virtual void SetConfirmedTargetAPZC(const LayerTransactionParent* aLayerTree,
diff --git a/gfx/layers/ipc/LayerTransactionParent.cpp b/gfx/layers/ipc/LayerTransactionParent.cpp
index d50e0b2183a6..e4f0225f8987 100644
--- a/gfx/layers/ipc/LayerTransactionParent.cpp
+++ b/gfx/layers/ipc/LayerTransactionParent.cpp
@@ -844,7 +844,7 @@ LayerTransactionParent::RecvSetAsyncZoom(const FrameMetrics::ViewID& aScrollID,
 mozilla::ipc::IPCResult
 LayerTransactionParent::RecvFlushApzRepaints()
 {
-  mCompositorBridge->FlushApzRepaints(this);
+  mCompositorBridge->FlushApzRepaints(GetId());
   return IPC_OK();
 }