diff --git a/ChangeLog b/ChangeLog
index 5c204ee90..199556c5f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2013-12-31  Marcus Mueller <znek@mulle-kybernetik.com>
+
+	* Headers/Foundation/NSMetadata.h: use GS_PROTOCOLS_HAVE_OPTIONAL for
+	NSMetadataQueryDelegate. Always define the protocol, even if it's empty
+	(so we don't have to adjust any headers), but fallback to the informal
+	protocol if OS version < 10.6 OR compiler doesn't support @optional
+	keyword in protocols.
+
 2013-12-30  Marcus Mueller <znek@mulle-kybernetik.com>
 
 	* Headers/GNUstepBase/GSVersionMacros.h: added macros
diff --git a/Headers/Foundation/NSMetadata.h b/Headers/Foundation/NSMetadata.h
index ddb91a9f1..29c835fc0 100644
--- a/Headers/Foundation/NSMetadata.h
+++ b/Headers/Foundation/NSMetadata.h
@@ -26,6 +26,7 @@
 
 #ifndef __NSMetadata_h_GNUSTEP_BASE_INCLUDE
 #define __NSMetadata_h_GNUSTEP_BASE_INCLUDE
+#import	<GNUstepBase/GSVersionMacros.h>
 
 #import <Foundation/NSObject.h>
 #import <Foundation/NSTimer.h>
@@ -129,9 +130,12 @@ GS_EXPORT NSString * const NSMetadataQueryGatheringProgressNotification;
 @end
 
 @protocol NSMetadataQueryDelegate
-#ifdef __OBJC2__
+#if OS_API_VERSION(MAC_OS_X_VERSION_10_6,GS_API_LATEST) && GS_PROTOCOLS_HAVE_OPTIONAL
 @optional
-#endif
+#else
+@end
+@interface NSObject (NSMetadataQueryDelegate)
+#endif // GS_PROTOCOLS_HAVE_OPTIONAL
 - (id) metadataQuery: (NSMetadataQuery *)query
   replacementObjectForResultObject: (NSMetadataItem *)result;
 - (id) metadataQuery: (NSMetadataQuery *)query