@@ -25,12 +25,12 @@
 {
 	return [[[self alloc] initWithFirstObject: firstObject
 				     secondObject: secondObject] autorelease];
 }
 
-- initWithFirstObject: (id)firstObject
-	 secondObject: (id)secondObject
+- (instancetype)initWithFirstObject: (id)firstObject
+		       secondObject: (id)secondObject
 {
 	self = [super init];
 
 	@try {
 		_firstObject = [firstObject retain];
@@ -93,16 +93,16 @@
 	OF_HASH_FINALIZE(hash);
 
 	return hash;
 }
 
-- copy
+- (id)copy
 {
 	return [self retain];
 }
 
-- mutableCopy
+- (id)mutableCopy
 {
 	return [[OFMutablePair alloc] initWithFirstObject: _firstObject
 					     secondObject: _secondObject];
 }