diff --git a/src/__phutil_library_map__.php b/src/__phutil_library_map__.php
--- a/src/__phutil_library_map__.php
+++ b/src/__phutil_library_map__.php
@@ -2755,6 +2755,7 @@
     'PhabricatorEmojiRemarkupRule' => 'applications/macro/markup/PhabricatorEmojiRemarkupRule.php',
     'PhabricatorEmojiTranslation' => 'infrastructure/internationalization/translation/PhabricatorEmojiTranslation.php',
     'PhabricatorEmptyQueryException' => 'infrastructure/query/PhabricatorEmptyQueryException.php',
+    'PhabricatorEnumConfigType' => 'applications/config/type/PhabricatorEnumConfigType.php',
     'PhabricatorEnv' => 'infrastructure/env/PhabricatorEnv.php',
     'PhabricatorEnvTestCase' => 'infrastructure/env/__tests__/PhabricatorEnvTestCase.php',
     'PhabricatorEpochEditField' => 'applications/transactions/editfield/PhabricatorEpochEditField.php',
@@ -4069,6 +4070,7 @@
     'PhabricatorStoragePatch' => 'infrastructure/storage/management/PhabricatorStoragePatch.php',
     'PhabricatorStorageSchemaSpec' => 'infrastructure/storage/schema/PhabricatorStorageSchemaSpec.php',
     'PhabricatorStorageSetupCheck' => 'applications/config/check/PhabricatorStorageSetupCheck.php',
+    'PhabricatorStringConfigType' => 'applications/config/type/PhabricatorStringConfigType.php',
     'PhabricatorStringListEditField' => 'applications/transactions/editfield/PhabricatorStringListEditField.php',
     'PhabricatorStringSetting' => 'applications/settings/setting/PhabricatorStringSetting.php',
     'PhabricatorSubmitEditField' => 'applications/transactions/editfield/PhabricatorSubmitEditField.php',
@@ -8044,6 +8046,7 @@
     'PhabricatorEmojiRemarkupRule' => 'PhutilRemarkupRule',
     'PhabricatorEmojiTranslation' => 'PhutilTranslation',
     'PhabricatorEmptyQueryException' => 'Exception',
+    'PhabricatorEnumConfigType' => 'PhabricatorTextConfigType',
     'PhabricatorEnv' => 'Phobject',
     'PhabricatorEnvTestCase' => 'PhabricatorTestCase',
     'PhabricatorEpochEditField' => 'PhabricatorEditField',
@@ -9605,6 +9608,7 @@
     'PhabricatorStoragePatch' => 'Phobject',
     'PhabricatorStorageSchemaSpec' => 'PhabricatorConfigSchemaSpec',
     'PhabricatorStorageSetupCheck' => 'PhabricatorSetupCheck',
+    'PhabricatorStringConfigType' => 'PhabricatorTextConfigType',
     'PhabricatorStringListEditField' => 'PhabricatorEditField',
     'PhabricatorStringSetting' => 'PhabricatorSetting',
     'PhabricatorSubmitEditField' => 'PhabricatorEditField',
diff --git a/src/applications/config/controller/PhabricatorConfigEditController.php b/src/applications/config/controller/PhabricatorConfigEditController.php
--- a/src/applications/config/controller/PhabricatorConfigEditController.php
+++ b/src/applications/config/controller/PhabricatorConfigEditController.php
@@ -285,7 +285,7 @@
           $canonical_value = $type->newValueFromRequestValue(
             $option,
             $value);
-          $type->validateStoredValue($canonical_value);
+          $type->validateStoredValue($option, $canonical_value);
           $xaction = $type->newTransaction($option, $canonical_value);
         } catch (PhabricatorConfigValidationException $ex) {
           $errors[] = $ex->getMessage();
@@ -347,10 +347,6 @@
       $set_value = null;
 
       switch ($type) {
-        case 'string':
-        case 'enum':
-          $set_value = (string)$value;
-          break;
         case 'list<string>':
         case 'list<regex>':
           $set_value = phutil_split_lines(
@@ -441,8 +437,6 @@
     } else {
       $type = $option->getType();
       switch ($type) {
-        case 'string':
-        case 'enum':
         case 'class':
           return $value;
         case 'bool':
@@ -479,9 +473,6 @@
     } else {
       $type = $option->getType();
       switch ($type) {
-        case 'string':
-          $control = id(new AphrontFormTextControl());
-          break;
         case 'bool':
           $control = id(new AphrontFormSelectControl())
             ->setOptions(
@@ -491,15 +482,6 @@
                 'false' => idx($option->getBoolOptions(), 1),
               ));
           break;
-        case 'enum':
-          $options = array_mergev(
-            array(
-              array('' => pht('(Use Default)')),
-              $option->getEnumOptions(),
-            ));
-          $control = id(new AphrontFormSelectControl())
-            ->setOptions($options);
-          break;
         case 'class':
           $symbols = id(new PhutilSymbolLoader())
             ->setType('class')
diff --git a/src/applications/config/management/PhabricatorConfigManagementSetWorkflow.php b/src/applications/config/management/PhabricatorConfigManagementSetWorkflow.php
--- a/src/applications/config/management/PhabricatorConfigManagementSetWorkflow.php
+++ b/src/applications/config/management/PhabricatorConfigManagementSetWorkflow.php
@@ -71,9 +71,7 @@
     } else {
       $type = $option->getType();
       switch ($type) {
-        case 'string':
         case 'class':
-        case 'enum':
           $value = (string)$value;
           break;
         case 'bool':
diff --git a/src/applications/config/option/PhabricatorApplicationConfigOptions.php b/src/applications/config/option/PhabricatorApplicationConfigOptions.php
--- a/src/applications/config/option/PhabricatorApplicationConfigOptions.php
+++ b/src/applications/config/option/PhabricatorApplicationConfigOptions.php
@@ -52,14 +52,6 @@
               $option->getKey()));
         }
         break;
-      case 'string':
-        if (!is_string($value)) {
-          throw new PhabricatorConfigValidationException(
-            pht(
-              "Option '%s' is of type string, but value is not a string.",
-              $option->getKey()));
-        }
-        break;
       case 'class':
         $symbols = id(new PhutilSymbolLoader())
           ->setType('class')
diff --git a/src/applications/config/option/PhabricatorMetaMTAConfigOptions.php b/src/applications/config/option/PhabricatorMetaMTAConfigOptions.php
--- a/src/applications/config/option/PhabricatorMetaMTAConfigOptions.php
+++ b/src/applications/config/option/PhabricatorMetaMTAConfigOptions.php
@@ -297,9 +297,9 @@
       $this->newOption('metamta.user-address-format', 'enum', 'full')
         ->setEnumOptions(
           array(
-            'short' => 'short',
-            'real' => 'real',
-            'full' => 'full',
+            'short' => pht('Short'),
+            'real' => pht('Real'),
+            'full' => pht('Full'),
           ))
         ->setSummary(pht('Control how Phabricator renders user names in mail.'))
         ->setDescription($address_description)
diff --git a/src/applications/config/option/PhabricatorUIConfigOptions.php b/src/applications/config/option/PhabricatorUIConfigOptions.php
--- a/src/applications/config/option/PhabricatorUIConfigOptions.php
+++ b/src/applications/config/option/PhabricatorUIConfigOptions.php
@@ -21,12 +21,12 @@
 
   public function getOptions() {
     $options = array(
-      'blindigo' => 'blindigo',
-      'red' => 'red',
-      'blue' => 'blue',
-      'green' => 'green',
-      'indigo' => 'indigo',
-      'dark' => 'dark',
+      'blindigo' => pht('Blindigo'),
+      'red' => pht('Red'),
+      'blue' => pht('Blue'),
+      'green' => pht('Green'),
+      'indigo' => pht('Indigo'),
+      'dark' => pht('Dark'),
     );
 
     $example = <<<EOJSON
diff --git a/src/applications/config/type/PhabricatorEnumConfigType.php b/src/applications/config/type/PhabricatorEnumConfigType.php
new file mode 100644
--- /dev/null
+++ b/src/applications/config/type/PhabricatorEnumConfigType.php
@@ -0,0 +1,43 @@
+<?php
+
+final class PhabricatorEnumConfigType
+  extends PhabricatorTextConfigType {
+
+  const TYPEKEY = 'enum';
+
+  public function validateStoredValue(
+    PhabricatorConfigOption $option,
+    $value) {
+
+    if (!is_string($value)) {
+      throw $this->newException(
+        pht(
+          'Option "%s" is of type "%s", but the configured value is not '.
+          'a string.',
+          $option->getKey(),
+          $this->getTypeKey()));
+    }
+
+    $map = $option->getEnumOptions();
+    if (!isset($map[$value])) {
+      throw $this->newException(
+        pht(
+          'Option "%s" is of type "%s", but the current value ("%s") is not '.
+          'among the set of valid values: %s.',
+          $option->getKey(),
+          $this->getTypeKey(),
+          $value,
+          implode(', ', array_keys($map))));
+    }
+  }
+
+  protected function newControl(PhabricatorConfigOption $option) {
+    $map = array(
+      '' => pht('(Use Default)'),
+    ) + $option->getEnumOptions();
+
+    return id(new AphrontFormSelectControl())
+      ->setOptions($map);
+  }
+
+}
diff --git a/src/applications/config/type/PhabricatorStringConfigType.php b/src/applications/config/type/PhabricatorStringConfigType.php
new file mode 100644
--- /dev/null
+++ b/src/applications/config/type/PhabricatorStringConfigType.php
@@ -0,0 +1,22 @@
+<?php
+
+final class PhabricatorStringConfigType
+  extends PhabricatorTextConfigType {
+
+  const TYPEKEY = 'string';
+
+  public function validateStoredValue(
+    PhabricatorConfigOption $option,
+    $value) {
+
+    if (!is_string($value)) {
+      throw $this->newException(
+        pht(
+          'Option "%s" is of type "%s", but the configured value is not '.
+          'a string.',
+          $option->getKey(),
+          $this->getTypeKey()));
+    }
+  }
+
+}
diff --git a/src/applications/config/type/PhabricatorTextConfigType.php b/src/applications/config/type/PhabricatorTextConfigType.php
--- a/src/applications/config/type/PhabricatorTextConfigType.php
+++ b/src/applications/config/type/PhabricatorTextConfigType.php
@@ -10,6 +10,12 @@
     return (bool)strlen($value);
   }
 
+  protected function newCanonicalValue(
+    PhabricatorConfigOption $option,
+    $value) {
+    return (string)$value;
+  }
+
   protected function newHTTPParameterType() {
     return new AphrontStringHTTPParameterType();
   }
diff --git a/src/applications/differential/config/PhabricatorDifferentialConfigOptions.php b/src/applications/differential/config/PhabricatorDifferentialConfigOptions.php
--- a/src/applications/differential/config/PhabricatorDifferentialConfigOptions.php
+++ b/src/applications/differential/config/PhabricatorDifferentialConfigOptions.php
@@ -260,7 +260,10 @@
         ->setDescription(
           pht('Format for inlined or attached patches.'))
         ->setEnumOptions(
-          array('unified' => 'unified', 'git' => 'git')),
+          array(
+            'unified' => pht('Unified'),
+            'git' => pht('Git'),
+          )),
     );
   }