diff --git a/infer/models/objc/src/NSData.m b/infer/models/objc/src/NSData.m
index 16993b23a..e67ac2e9e 100644
--- a/infer/models/objc/src/NSData.m
+++ b/infer/models/objc/src/NSData.m
@@ -14,7 +14,7 @@ NSData* __objc_alloc(NSData*);
 
 @interface NSData : NSObject
 
-@property (readonly) const void *bytes;
+@property (nonatomic, readonly) const void *bytes;
 
 + (instancetype)dataWithBytesNoCopy:(void *)bytes length:(NSUInteger)length;
 + (instancetype)dataWithBytesNoCopy:(void *)bytes length:(NSUInteger)length freeWhenDone:(BOOL)b;
diff --git a/infer/models/objc/src/NSFileHandle.m b/infer/models/objc/src/NSFileHandle.m
index 1edcad2ed..af7743ad0 100644
--- a/infer/models/objc/src/NSFileHandle.m
+++ b/infer/models/objc/src/NSFileHandle.m
@@ -20,7 +20,7 @@
 
 - (instancetype)initWithFileDescriptor:(int)fd;
 
-@property (readonly) int fileDescriptor;
+@property (nonatomic, readonly) int fileDescriptor;
 
 @end