diff --git a/com.unity.render-pipelines.high-definition/CHANGELOG.md b/com.unity.render-pipelines.high-definition/CHANGELOG.md
index 8a583aaffe3..780f4952e50 100644
--- a/com.unity.render-pipelines.high-definition/CHANGELOG.md
+++ b/com.unity.render-pipelines.high-definition/CHANGELOG.md
@@ -583,6 +583,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Fixed issue with reflection probes in realtime time mode with OnEnable baking having wrong lighting with sky set to dynamic (case 1238047).
 - Fixed transparent motion vectors not working when in MSAA.
 - Fix error when removing DecalProjector from component contextual menu (case 1243960)
+- Fixed issue with post process when running in RGBA16 and an object with additive blending is in the scene.
 
 ### Changed
 - Improve MIP selection for decals on Transparents
diff --git a/com.unity.render-pipelines.high-definition/Runtime/PostProcessing/Shaders/UberPost.compute b/com.unity.render-pipelines.high-definition/Runtime/PostProcessing/Shaders/UberPost.compute
index 223aeabc3fc..8a0b252c5a1 100644
--- a/com.unity.render-pipelines.high-definition/Runtime/PostProcessing/Shaders/UberPost.compute
+++ b/com.unity.render-pipelines.high-definition/Runtime/PostProcessing/Shaders/UberPost.compute
@@ -218,7 +218,8 @@ void Uber(uint3 dispatchThreadId : SV_DispatchThreadID)
     // Alpha mask
 #ifdef ENABLE_ALPHA
         // Post processing is not applied on pixels with zero alpha
-        color.xyz = lerp(inputColor.xyz, color.xyz, inputColor.a);
+        // Saturate is necessary to avoid issues when additive blending pushes the alpha over 1.
+        color.xyz = lerp(inputColor.xyz, color.xyz, saturate(inputColor.a));
 #endif
 
     // Done