diff --git a/resources/shaders/glsl/core.glsl b/resources/shaders/glsl/core.glsl
index b17415b03..9e60a02d2 100644
--- a/resources/shaders/glsl/core.glsl
+++ b/resources/shaders/glsl/core.glsl
@@ -73,6 +73,7 @@ void main()
 
     // Brightness.
     if (brightness != 0.0) {
+        sampledColor.rgb /= sampledColor.a;
         sampledColor.rgb += 0.3 * brightness;
         sampledColor.rgb *= sampledColor.a;
     }
diff --git a/resources/shaders/glsl/scanlines.glsl b/resources/shaders/glsl/scanlines.glsl
index 923e70290..39df227f4 100644
--- a/resources/shaders/glsl/scanlines.glsl
+++ b/resources/shaders/glsl/scanlines.glsl
@@ -158,6 +158,7 @@ void main()
 
     // Brightness.
     if (brightness != 0.0) {
+        colorTemp.rgb /= colorTemp.a;
         colorTemp.rgb += 0.3 * brightness;
         colorTemp.rgb *= colorTemp.a;
     }