diff --git a/Source/Shaders/CmSVGFTemporalAccumulation.comp b/Source/Shaders/CmSVGFTemporalAccumulation.comp
index 74328fa7..6d7123c2 100644
--- a/Source/Shaders/CmSVGFTemporalAccumulation.comp
+++ b/Source/Shaders/CmSVGFTemporalAccumulation.comp
@@ -228,12 +228,12 @@ void main()
 
         // specular
         {
-            // const float roughness = texelFetch(framebufMetallicRoughness_Sampler, pix, 0).g;
+            const float roughness = texelFetch(framebufMetallicRoughness_Sampler, pix, 0).g;
 
             // antilagAlpha_Spec *= (1 - roughness) * 0.9 + 0.1;
 
             specHistoryLength *= pow(1.0 - antilagAlpha_Spec, 5);
-            specHistoryLength = clamp(specHistoryLength + 1.0, 1.0, 64.0);
+            specHistoryLength = clamp(specHistoryLength + 1.0, 1.0, mix(8.0, 64.0, roughness));
 
             const float minAlpha = 0.01;
             float alphaColor = max(minAlpha, 1.0 / specHistoryLength);