diff --git a/modules/i18n/input-method/fcitx5.nix b/modules/i18n/input-method/fcitx5.nix
index a710dc49f..5f9a9aac2 100644
--- a/modules/i18n/input-method/fcitx5.nix
+++ b/modules/i18n/input-method/fcitx5.nix
@@ -222,7 +222,7 @@ in
           optionalFile =
             p: f: v:
             lib.optionalAttrs (v != { }) {
-              "fcitx5/${p}".source = f v;
+              "fcitx5/${p}".source = f "fcitx5-${builtins.replaceStrings [ "/" ] [ "-" ] p}" v;
             };
         in
         lib.attrsets.mergeAttrsList [
@@ -249,7 +249,7 @@ in
             else if builtins.isString attrs.theme then
               pkgs.writeText "fcitx5-theme.conf" attrs.theme
             else
-              iniFormat.generate attrs.theme
+              iniFormat.generate "fcitx5-${name}-theme" attrs.theme
           ))
         ]
       ) cfg.themes;
diff --git a/tests/modules/i18n/input-method/fcitx5/old-enable.nix b/tests/modules/i18n/input-method/fcitx5/old-enable.nix
index 0a6994264..b2a41141e 100644
--- a/tests/modules/i18n/input-method/fcitx5/old-enable.nix
+++ b/tests/modules/i18n/input-method/fcitx5/old-enable.nix
@@ -20,7 +20,7 @@ lib.mkIf config.test.enableBig {
           ScaleWithDPI=True
         '';
       };
-      classicUiConfig = "Theme=example";
+      settings.addons.classicui.globalSection.Theme = "example";
     };
   };
 
@@ -32,8 +32,8 @@ lib.mkIf config.test.enableBig {
 
   nmt.script = ''
     assertFileExists home-files/.config/systemd/user/fcitx5-daemon.service
+    assertFileExists home-files/.config/fcitx5/conf/classicui.conf
     assertFileExists home-files/.local/share/fcitx5/themes/example/theme.conf
-    assertFileExists home-files/.local/share/fcitx5/conf/classicui.conf
     assertFileNotRegex home-path/etc/profile.d/hm-session-vars.sh 'GTK_IM_MODULE'
     assertFileNotRegex home-path/etc/profile.d/hm-session-vars.sh 'QT_IM_MODULE'
   '';