diff --git a/TestProjects/HDRP_Tests/Assets/ReferenceImages/Linear/LinuxEditor/Vulkan/None/4053_TAA-FP16Alpha.png b/TestProjects/HDRP_Tests/Assets/ReferenceImages/Linear/LinuxEditor/Vulkan/None/4053_TAA-FP16Alpha.png
index cca086bcef3..de41dc14321 100644
--- a/TestProjects/HDRP_Tests/Assets/ReferenceImages/Linear/LinuxEditor/Vulkan/None/4053_TAA-FP16Alpha.png
+++ b/TestProjects/HDRP_Tests/Assets/ReferenceImages/Linear/LinuxEditor/Vulkan/None/4053_TAA-FP16Alpha.png
@@ -1,3 +1,3 @@
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-size 240651
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+size 204829
diff --git a/TestProjects/HDRP_Tests/Assets/ReferenceImages/Linear/WindowsEditor/Direct3D11/None/4053_TAA-FP16Alpha.png b/TestProjects/HDRP_Tests/Assets/ReferenceImages/Linear/WindowsEditor/Direct3D11/None/4053_TAA-FP16Alpha.png
index 8c2f382b5e4..b547eaad820 100644
--- a/TestProjects/HDRP_Tests/Assets/ReferenceImages/Linear/WindowsEditor/Direct3D11/None/4053_TAA-FP16Alpha.png
+++ b/TestProjects/HDRP_Tests/Assets/ReferenceImages/Linear/WindowsEditor/Direct3D11/None/4053_TAA-FP16Alpha.png
@@ -1,3 +1,3 @@
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-size 240678
+oid sha256:ec59d9a2dc4de6d09000dbfe3d736a0d97ba6f862840596d58f26b35b53661ea
+size 204811
diff --git a/TestProjects/HDRP_Tests/Assets/ReferenceImages/Linear/WindowsEditor/Direct3D12/None/4053_TAA-FP16Alpha.png b/TestProjects/HDRP_Tests/Assets/ReferenceImages/Linear/WindowsEditor/Direct3D12/None/4053_TAA-FP16Alpha.png
index 8c2f382b5e4..b547eaad820 100644
--- a/TestProjects/HDRP_Tests/Assets/ReferenceImages/Linear/WindowsEditor/Direct3D12/None/4053_TAA-FP16Alpha.png
+++ b/TestProjects/HDRP_Tests/Assets/ReferenceImages/Linear/WindowsEditor/Direct3D12/None/4053_TAA-FP16Alpha.png
@@ -1,3 +1,3 @@
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diff --git a/TestProjects/HDRP_Tests/Assets/ReferenceImages/Linear/WindowsEditor/Vulkan/None/4053_TAA-FP16Alpha.png b/TestProjects/HDRP_Tests/Assets/ReferenceImages/Linear/WindowsEditor/Vulkan/None/4053_TAA-FP16Alpha.png
index cca086bcef3..de41dc14321 100644
--- a/TestProjects/HDRP_Tests/Assets/ReferenceImages/Linear/WindowsEditor/Vulkan/None/4053_TAA-FP16Alpha.png
+++ b/TestProjects/HDRP_Tests/Assets/ReferenceImages/Linear/WindowsEditor/Vulkan/None/4053_TAA-FP16Alpha.png
@@ -1,3 +1,3 @@
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diff --git a/com.unity.render-pipelines.high-definition/CHANGELOG.md b/com.unity.render-pipelines.high-definition/CHANGELOG.md
index 96198ee3d42..ed3f4116836 100644
--- a/com.unity.render-pipelines.high-definition/CHANGELOG.md
+++ b/com.unity.render-pipelines.high-definition/CHANGELOG.md
@@ -216,6 +216,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Updated Light's shadow layer name in Editor.
 - Increased path tracing max samples from 4K to 16K (case 1327729).
 - Film grain does not affect the alpha channel.
+- Disable TAA sharpening on alpha channel.
 
 ## [11.0.0] - 2020-10-21
 
diff --git a/com.unity.render-pipelines.high-definition/Runtime/PostProcessing/Shaders/TemporalAntialiasing.hlsl b/com.unity.render-pipelines.high-definition/Runtime/PostProcessing/Shaders/TemporalAntialiasing.hlsl
index ebb6d9dbc35..a17d7891173 100644
--- a/com.unity.render-pipelines.high-definition/Runtime/PostProcessing/Shaders/TemporalAntialiasing.hlsl
+++ b/com.unity.render-pipelines.high-definition/Runtime/PostProcessing/Shaders/TemporalAntialiasing.hlsl
@@ -11,7 +11,6 @@
     #define CTYPE_SWIZZLE xyz
 #endif
 
-
 #if UNITY_REVERSED_Z
     #define COMPARE_DEPTH(a, b) step(b, a)
 #else
@@ -49,6 +48,8 @@ float4 Fetch4Array(Texture2DArray tex, uint slot, float2 coords, float2 offset,
 // Options
 // ---------------------------------------------------
 
+#define SHARPEN_ALPHA 0 // switch to 1 if you want to enable TAA sharpenning on alpha channel
+
 // History sampling options
 #define BILINEAR 0
 #define BICUBIC_5TAP 1
@@ -717,5 +718,11 @@ CTYPE SharpenColor(NeighbourhoodSamples samples, CTYPE color, float sharpenStren
     linearC = linearC + (linearC - linearAvg) * sharpenStrength * 3;
     linearC = clamp(linearC, 0, CLAMP_MAX);
 #endif
-    return linearC * PerceptualWeight(linearC);
+    CTYPE outputSharpened = linearC * PerceptualWeight(linearC);
+
+#if (SHARPEN_ALPHA == 0 && defined(ENABLE_ALPHA))
+    outputSharpened.a = color.a;
+#endif
+
+    return outputSharpened;
 }