diff --git a/pkgs/tools/inputmethods/fcitx5/with-addons.nix b/pkgs/tools/inputmethods/fcitx5/with-addons.nix
index e2870dc1f561..75fac87b6285 100644
--- a/pkgs/tools/inputmethods/fcitx5/with-addons.nix
+++ b/pkgs/tools/inputmethods/fcitx5/with-addons.nix
@@ -29,7 +29,7 @@ symlinkJoin {
       --suffix PATH : "$out/bin" \
       --suffix LD_LIBRARY_PATH : "${lib.makeLibraryPath (lib.flatten (map (x: x.extraLdLibraries or []) addons))}"
 
-    ${lib.optionals withConfigtool ''
+    ${lib.optionalString withConfigtool ''
       # Configtool call libexec/fcitx5-qt5-gui-wrapper for gui addons in FCITX_ADDON_DIRS
       wrapProgram $out/bin/fcitx5-config-qt --prefix FCITX_ADDON_DIRS : "$out/lib/fcitx5"
     ''}