diff --git a/services/surfaceflinger/Tracing/TransactionProtoParser.cpp b/services/surfaceflinger/Tracing/TransactionProtoParser.cpp
index 7e12313..783b36e 100644
--- a/services/surfaceflinger/Tracing/TransactionProtoParser.cpp
+++ b/services/surfaceflinger/Tracing/TransactionProtoParser.cpp
@@ -43,7 +43,7 @@
 }
 
 proto::TransactionState TransactionProtoParser::toProto(
-        const std::unordered_map<int32_t /* layerId */, TracingLayerState> states) {
+        const std::map<int32_t /* layerId */, TracingLayerState> states) {
     proto::TransactionState proto;
     for (auto& [layerId, state] : states) {
         proto::LayerState layerProto = toProto(state, nullptr);
diff --git a/services/surfaceflinger/Tracing/TransactionProtoParser.h b/services/surfaceflinger/Tracing/TransactionProtoParser.h
index 619ee05..16e9b5e 100644
--- a/services/surfaceflinger/Tracing/TransactionProtoParser.h
+++ b/services/surfaceflinger/Tracing/TransactionProtoParser.h
@@ -51,7 +51,7 @@
     static proto::TransactionState toProto(const TransactionState&, LayerHandleToIdFn getLayerIdFn,
                                            DisplayHandleToIdFn getDisplayIdFn);
     static proto::TransactionState toProto(
-            const std::unordered_map<int32_t /* layerId */, TracingLayerState>);
+            const std::map<int32_t /* layerId */, TracingLayerState>);
 
     static proto::LayerCreationArgs toProto(const TracingLayerCreationArgs& args);
 
diff --git a/services/surfaceflinger/Tracing/TransactionTracing.h b/services/surfaceflinger/Tracing/TransactionTracing.h
index 0aa22ed..546ac7a 100644
--- a/services/surfaceflinger/Tracing/TransactionTracing.h
+++ b/services/surfaceflinger/Tracing/TransactionTracing.h
@@ -85,8 +85,7 @@
     std::vector<proto::LayerCreationArgs> mCreatedLayers GUARDED_BY(mTraceLock);
     std::unordered_map<BBinder* /* layerHandle */, int32_t /* layerId */> mLayerHandles
             GUARDED_BY(mTraceLock);
-    std::unordered_map<int32_t /* layerId */, TracingLayerState> mStartingStates
-            GUARDED_BY(mTraceLock);
+    std::map<int32_t /* layerId */, TracingLayerState> mStartingStates GUARDED_BY(mTraceLock);
 
     // We do not want main thread to block so main thread will try to acquire mMainThreadLock,
     // otherwise will push data to temporary container.
diff --git a/services/surfaceflinger/tests/unittests/TransactionTracingTest.cpp b/services/surfaceflinger/tests/unittests/TransactionTracingTest.cpp
index ffe5671..4e49c18 100644
--- a/services/surfaceflinger/tests/unittests/TransactionTracingTest.cpp
+++ b/services/surfaceflinger/tests/unittests/TransactionTracingTest.cpp
@@ -165,7 +165,7 @@
         mTracing->onLayerAdded(fakeLayerHandle->localBinder(), mParentLayerId, "parent",
                                123 /* flags */, -1 /* parentId */);
         const sp<IBinder> fakeChildLayerHandle = new BBinder();
-        mTracing->onLayerAdded(fakeChildLayerHandle->localBinder(), 2 /* layerId */, "child",
+        mTracing->onLayerAdded(fakeChildLayerHandle->localBinder(), mChildLayerId, "child",
                                456 /* flags */, mParentLayerId);
 
         // add some layer transaction
@@ -179,7 +179,8 @@
             transaction.states.add(layerState);
             ComposerState childState;
             childState.state.surface = fakeChildLayerHandle;
-            layerState.state.z = 43;
+            childState.state.what = layer_state_t::eLayerChanged;
+            childState.state.z = 43;
             transaction.states.add(childState);
             mTracing->addQueuedTransaction(transaction);
 
@@ -227,6 +228,7 @@
     }
 
     int mParentLayerId = 1;
+    int mChildLayerId = 2;
     int64_t mVsyncId = 0;
     int64_t VSYNC_ID_FIRST_LAYER_CHANGE;
     int64_t VSYNC_ID_SECOND_LAYER_CHANGE;
@@ -244,8 +246,11 @@
     EXPECT_GT(proto.entry().size(), 0);
     EXPECT_GT(proto.entry(0).transactions().size(), 0);
     EXPECT_GT(proto.entry(0).added_layers().size(), 0);
-    EXPECT_GT(proto.entry(0).transactions(0).layer_changes().size(), 0);
+    EXPECT_EQ(proto.entry(0).transactions(0).layer_changes().size(), 2);
+    EXPECT_EQ(proto.entry(0).transactions(0).layer_changes(0).layer_id(), mParentLayerId);
     EXPECT_EQ(proto.entry(0).transactions(0).layer_changes(0).z(), 42);
+    EXPECT_EQ(proto.entry(0).transactions(0).layer_changes(1).layer_id(), mChildLayerId);
+    EXPECT_EQ(proto.entry(0).transactions(0).layer_changes(1).z(), 43);
 }
 
 TEST_F(TransactionTracingLayerHandlingTest, updateStartingState) {