ARC weak weird behavior

Child.h

@interface Child : NSObject

@property (nonatomic, weak, readonly) Parent* parent;

- (id)initWithParent:(Parent*)parent;

@end

Child.m

#import "Child.h"


@interface Child ()

@property (nonatomic, weak) Parent* parent;

@end


@implementation Child

@synthesize parent = _parent;

#pragma mark - Initialization

- (id)initWithParent:(Parent*)parent
{
	if ((self = [super init]))
	{
		[self setParent:parent];
	}
	
	return self;
}

@end

Test.m

Parent* parent = [Parent new];
Child* child = [[Child alloc] initWithParent:parent];
NSAssert([child parent] == parent, nil); // ERROR: [child parent] == nil