diff --git a/Source/OEGameCoreManager.h b/Source/OEGameCoreManager.h
index 9002359..f4595b7 100644
--- a/Source/OEGameCoreManager.h
+++ b/Source/OEGameCoreManager.h
@@ -31,7 +31,11 @@
 @protocol OEGameCoreOwner;
 @class OECorePlugin, OEGameCoreController, OESystemPlugin, OEGameStartupInfo;
 
-enum _OEGameCoreManagerErrorCodes
+NS_ASSUME_NONNULL_BEGIN
+
+extern NSString * const OEGameCoreErrorDomain;
+
+typedef NS_ERROR_ENUM(OEGameCoreErrorDomain, OEGameCoreManagerErrorCodes)
 {
     OEHelperAppNotRunningError     = -3,
     OEConnectionTimedOutError      = -4,
@@ -39,10 +43,6 @@ enum _OEGameCoreManagerErrorCodes
     OENilRootProxyObjectError      = -6,
 };
 
-NS_ASSUME_NONNULL_BEGIN
-
-extern NSString * const OEGameCoreErrorDomain;
-
 @interface OEGameCoreManager : NSObject <OEGameCoreHelper>
 
 /*! @brief Initializes an @c OEGameCoreManager object with the specified parameters.