diff --git a/modules/services/compton.nix b/modules/services/compton.nix
index c5b96af34..3a67c7cb5 100644
--- a/modules/services/compton.nix
+++ b/modules/services/compton.nix
@@ -34,6 +34,7 @@ let
     # opacity
     active-opacity   = ${cfg.activeOpacity};
     inactive-opacity = ${cfg.inactiveOpacity};
+    inactive-dim     = ${cfg.inactiveDim};
     menu-opacity     = ${cfg.menuOpacity};
     opacity-rule     = ${toJSON cfg.opacityRule};
 
@@ -178,6 +179,15 @@ in {
       '';
     };
 
+    inactiveDim = mkOption {
+      type = types.str;
+      default = "0.0";
+      example = "0.2";
+      description = ''
+        Dim inactive windows.
+      '';
+    };
+
     inactiveOpacity = mkOption {
       type = types.str;
       default = "1.0";