diff --git a/modules/services/picom.nix b/modules/services/picom.nix
index 280a2a21e..d4702d3ed 100644
--- a/modules/services/picom.nix
+++ b/modules/services/picom.nix
@@ -270,7 +270,7 @@ in {
     };
 
     extraOptions = mkOption {
-      type = types.str;
+      type = types.lines;
       default = "";
       example = ''
         unredir-if-possible = true;