diff --git a/lib/tests/modules.sh b/lib/tests/modules.sh
index 318efc4c3d05..b1994ff31638 100755
--- a/lib/tests/modules.sh
+++ b/lib/tests/modules.sh
@@ -105,12 +105,12 @@ checkConfigError '.*A definition for option .bad. is not of type .non-empty .lis
 
 # types.attrTag
 checkConfigOutput '^true$' config.okChecks ./types-attrTag.nix
-checkConfigError 'A definition for option .intStrings\.syntaxError. is not of type .attribute-tagged union of left, right' config.intStrings.syntaxError ./types-attrTag.nix
-checkConfigError 'A definition for option .intStrings\.syntaxError2. is not of type .attribute-tagged union of left, right' config.intStrings.syntaxError2 ./types-attrTag.nix
-checkConfigError 'A definition for option .intStrings\.syntaxError3. is not of type .attribute-tagged union of left, right' config.intStrings.syntaxError3 ./types-attrTag.nix
-checkConfigError 'A definition for option .intStrings\.syntaxError4. is not of type .attribute-tagged union of left, right' config.intStrings.syntaxError4 ./types-attrTag.nix
-checkConfigError 'A definition for option .intStrings\.mergeError. is not of type .attribute-tagged union of left, right' config.intStrings.mergeError ./types-attrTag.nix
-checkConfigError 'A definition for option .intStrings\.badTagError. is not of type .attribute-tagged union of left, right' config.intStrings.badTagError ./types-attrTag.nix
+checkConfigError 'A definition for option .intStrings\.syntaxError. is not of type .attribute-tagged union' config.intStrings.syntaxError ./types-attrTag.nix
+checkConfigError 'A definition for option .intStrings\.syntaxError2. is not of type .attribute-tagged union' config.intStrings.syntaxError2 ./types-attrTag.nix
+checkConfigError 'A definition for option .intStrings\.syntaxError3. is not of type .attribute-tagged union' config.intStrings.syntaxError3 ./types-attrTag.nix
+checkConfigError 'A definition for option .intStrings\.syntaxError4. is not of type .attribute-tagged union' config.intStrings.syntaxError4 ./types-attrTag.nix
+checkConfigError 'A definition for option .intStrings\.mergeError. is not of type .attribute-tagged union' config.intStrings.mergeError ./types-attrTag.nix
+checkConfigError 'A definition for option .intStrings\.badTagError. is not of type .attribute-tagged union' config.intStrings.badTagError ./types-attrTag.nix
 checkConfigError 'A definition for option .intStrings\.badTagTypeError\.left. is not of type .signed integer.' config.intStrings.badTagTypeError.left ./types-attrTag.nix
 checkConfigError 'A definition for option .nested\.right\.left. is not of type .signed integer.' config.nested.right.left ./types-attrTag.nix
 
diff --git a/lib/types.nix b/lib/types.nix
index 02532a991e98..7fe7b5d92eac 100644
--- a/lib/types.nix
+++ b/lib/types.nix
@@ -644,7 +644,8 @@ rec {
       in
       mkOptionType {
         name = "attrTag";
-        description = "attribute-tagged union of ${choicesStr}";
+        description = "attribute-tagged union";
+        descriptionClass = "noun";
         getSubOptions = prefix:
           mapAttrs
             (tagName: tagOption: {