TL;DR What was the correct was to access a Objective-C @property (...) foo as foo instead of self.foo?

Details:

One of my iOS project still uses some Objective-C code I have written several years ago.

// SomeObject.h
@interface SomeObject : NSObject
@property (nonatomic, readonly) NSString *foo;
@end

// SomeObject.m
@implementation SomeObject { ... }
@synthesize foo;

- (void)someMethod {
   foo = @"bar";
}

- (void)otherMethod {
   NSLog(@"Foo: %@", foo);  // ---> "bar"
}
@end

This works fine as intended. Now I would like to use a getter to access some new Swift code instead of setting foo manually:

// SomeObject.m
@implementation SomeObject { ... }
@synthesize foo;

- (NSString *)foo {
   return [SwiftObject getFoo];
}

- (void)otherMethod {
   NSLog(@"Foo: %@", foo);  // ---> nil
   NSLog(@"Foo: %@", self.foo);  // ---> "swiftBar"
}
@end

So, using the getter only works correct when using self.foo instead of just foo. This is not a big problem but it would require to replaces all usage of foo with self.foo in the existing code.

Is there a clean way to avoid this, use the foo getter and still use foo instead of self.foo?