diff --git a/Headers/Foundation/NSKeyValueCoding.h b/Headers/Foundation/NSKeyValueCoding.h
index fecbc45c1..906aa8e5b 100644
--- a/Headers/Foundation/NSKeyValueCoding.h
+++ b/Headers/Foundation/NSKeyValueCoding.h
@@ -342,7 +342,7 @@ GS_EXPORT NSString* const NSUndefinedKeyException;
  */
 - (BOOL) validateValue: (id*)aValue
 		forKey: (NSString*)aKey
-		 error: (NSError**)anError;
+		 error: (out NSError**)anError;
 
 /**
  * Returns the result of calling -validateValue:forKey:error: on the receiver
@@ -351,7 +351,7 @@ GS_EXPORT NSString* const NSUndefinedKeyException;
  */
 - (BOOL) validateValue: (id*)aValue
 	    forKeyPath: (NSString*)aKey
-		 error: (NSError**)anError;
+		 error: (out NSError**)anError;
 
 /**
  * Returns the value associated with the supplied key as an object.
diff --git a/Headers/Foundation/NSPropertyList.h b/Headers/Foundation/NSPropertyList.h
index 594404f93..17e3f226a 100644
--- a/Headers/Foundation/NSPropertyList.h
+++ b/Headers/Foundation/NSPropertyList.h
@@ -265,20 +265,20 @@ typedef NSUInteger NSPropertyListFormat;
 + (NSData *) dataWithPropertyList: (id)aPropertyList
                            format: (NSPropertyListFormat)aFormat
                           options: (NSPropertyListWriteOptions)anOption
-                            error: (NSError**)error;
+                            error: (out NSError**)error;
 + (id) propertyListWithData: (NSData*)data
                     options: (NSPropertyListReadOptions)anOption
                      format: (NSPropertyListFormat*)aFormat
-                      error: (NSError**)error;
+                      error: (out NSError**)error;
 + (id) propertyListWithStream: (NSInputStream*)stream
                       options: (NSPropertyListReadOptions)anOption
                        format: (NSPropertyListFormat*)aFormat
-                        error: (NSError**)error;
+                        error: (out NSError**)error;
 + (NSInteger) writePropertyList: (id)aPropertyList
                        toStream: (NSOutputStream*)stream
                          format: (NSPropertyListFormat)aFormat
                         options: (NSPropertyListWriteOptions)anOption
-                          error: (NSError**)error;
+                          error: (out NSError**)error;
 #endif
 
 @end