diff --git a/Formatter/SwaggerFormatter.php b/Formatter/SwaggerFormatter.php
index 65248eb..532249a 100644
--- a/Formatter/SwaggerFormatter.php
+++ b/Formatter/SwaggerFormatter.php
@@ -342,7 +342,9 @@ class SwaggerFormatter implements FormatterInterface
                 switch ($prop['actualType']) {
                     case DataTypes::ENUM:
                         $type = 'string';
-                        $enum = array_keys(json_decode($prop['format'], true));
+                        if (isset($prop['format'])) {
+                            $enum = array_keys(json_decode($prop['format'], true));
+                        }
                         break;
 
                     case DataTypes::MODEL:
diff --git a/Resources/doc/swagger-support.md b/Resources/doc/swagger-support.md
index f45d0dd..b2b50fe 100644
--- a/Resources/doc/swagger-support.md
+++ b/Resources/doc/swagger-support.md
@@ -83,7 +83,7 @@ The routes registered with the method above will read your `@ApiDoc` annotation
 php app/console api:swagger:dump --all app/Resources/swagger-docs
 ```
 
-The above command will dump JSON files under the `app/Resources/swagger-docs` directory (relative to your project root), and you can now process or server the files however you want. (If the destination defaults to the project root if not specified.)
+The above command will dump JSON files under the `app/Resources/swagger-docs` directory (relative to your project root), and you can now process or server the files however you want. The destination defaults to the project root if not specified.
 
 ####Selective dumps