diff --git a/services/surfaceflinger/tests/unittests/LayerHierarchyTest.h b/services/surfaceflinger/tests/unittests/LayerHierarchyTest.h
index d7ac038..1898f43 100644
--- a/services/surfaceflinger/tests/unittests/LayerHierarchyTest.h
+++ b/services/surfaceflinger/tests/unittests/LayerHierarchyTest.h
@@ -406,6 +406,17 @@
         mLifecycleManager.applyTransactions(transactions);
     }
 
+    void setShadowRadius(uint32_t id, float shadowRadius) {
+        std::vector<TransactionState> transactions;
+        transactions.emplace_back();
+        transactions.back().states.push_back({});
+
+        transactions.back().states.front().state.what = layer_state_t::eShadowRadiusChanged;
+        transactions.back().states.front().layerId = id;
+        transactions.back().states.front().state.shadowRadius = shadowRadius;
+        mLifecycleManager.applyTransactions(transactions);
+    }
+
     LayerLifecycleManager mLifecycleManager;
 };
 
diff --git a/services/surfaceflinger/tests/unittests/LayerSnapshotTest.cpp b/services/surfaceflinger/tests/unittests/LayerSnapshotTest.cpp
index 69316bf..2ae0131 100644
--- a/services/surfaceflinger/tests/unittests/LayerSnapshotTest.cpp
+++ b/services/surfaceflinger/tests/unittests/LayerSnapshotTest.cpp
@@ -872,4 +872,13 @@
     UPDATE_AND_VERIFY(mSnapshotBuilder, STARTING_ZORDER);
     EXPECT_EQ(getSnapshot(1)->geomContentCrop, Rect(0, 0, 100, 100));
 }
+
+TEST_F(LayerSnapshotTest, setShadowRadius) {
+    static constexpr float SHADOW_RADIUS = 123.f;
+    setShadowRadius(1, SHADOW_RADIUS);
+    UPDATE_AND_VERIFY(mSnapshotBuilder, STARTING_ZORDER);
+    EXPECT_EQ(getSnapshot(1)->shadowSettings.length, SHADOW_RADIUS);
+    EXPECT_EQ(getSnapshot(1)->shadowRadius, SHADOW_RADIUS);
+}
+
 } // namespace android::surfaceflinger::frontend