diff --git a/RCTAppleHealthKit/RCTAppleHealthKit+Methods_Fitness.h b/RCTAppleHealthKit/RCTAppleHealthKit+Methods_Fitness.h
index bf37c55c6b13f8ae4c3cd1df2cabc95bdd048408..32fb563c2ceabfc5cddb294b56aa0bc92060c903 100644
--- a/RCTAppleHealthKit/RCTAppleHealthKit+Methods_Fitness.h
+++ b/RCTAppleHealthKit/RCTAppleHealthKit+Methods_Fitness.h
@@ -12,7 +12,7 @@
 
 - (void)fitness_getStepCountOnDay:(NSDictionary *)input callback:(RCTResponseSenderBlock)callback;
 - (void)fitness_getSamples:(NSDictionary *)input callback:(RCTResponseSenderBlock)callback;
-- (void)fitness_setObserver:(NSDictionary *)input callback:(RCTResponseSenderBlock)callback;
+- (void)fitness_setObserver:(NSDictionary *)input;
 - (void)fitness_getDailyStepSamples:(NSDictionary *)input callback:(RCTResponseSenderBlock)callback;
 - (void)fitness_saveSteps:(NSDictionary *)input callback:(RCTResponseSenderBlock)callback;
 - (void)fitness_initializeStepEventObserver:(NSDictionary *)input callback:(RCTResponseSenderBlock)callback;
diff --git a/RCTAppleHealthKit/RCTAppleHealthKit+Methods_Fitness.m b/RCTAppleHealthKit/RCTAppleHealthKit+Methods_Fitness.m
index 5e6fc0d7c4ecff9784bcfe180a28921fffc7b543..294c9f1603ae4ada4ce42838816c08d4fa89fa44 100644
--- a/RCTAppleHealthKit/RCTAppleHealthKit+Methods_Fitness.m
+++ b/RCTAppleHealthKit/RCTAppleHealthKit+Methods_Fitness.m
@@ -91,7 +91,7 @@
                           }];
 }
 
-- (void)fitness_setObserver:(NSDictionary *)input callback:(RCTResponseSenderBlock)callback
+- (void)fitness_setObserver:(NSDictionary *)input
 {
     HKUnit *unit = [RCTAppleHealthKit hkUnitFromOptions:input key:@"unit" withDefault:[HKUnit countUnit]];
     NSString *type = [RCTAppleHealthKit stringFromOptions:input key:@"type" withDefault:@"Walking"];
@@ -111,9 +111,7 @@
         samplesType = [HKObjectType workoutType];
     }
     
-    [self setObserverForType:samplesType unit:unit completion:^(NSArray *results, NSError * error) {
-        callback(@[[NSNull null], results]);
-    }];
+    [self setObserverForType:samplesType unit:unit];
 }
 
 
diff --git a/RCTAppleHealthKit/RCTAppleHealthKit+Queries.h b/RCTAppleHealthKit/RCTAppleHealthKit+Queries.h
index 8eec34b4a6e4739025ea621ed1759ed554315f5a..381a82c5b778988beb1376810c2b383f4198203d 100644
--- a/RCTAppleHealthKit/RCTAppleHealthKit+Queries.h
+++ b/RCTAppleHealthKit/RCTAppleHealthKit+Queries.h
@@ -27,8 +27,7 @@
                              limit:(NSUInteger)lim
                         completion:(void (^)(NSArray *, NSError *))completion;
 - (void)setObserverForType:(HKSampleType *)quantityType
-                      unit:(HKUnit *)unit
-                completion:(void (^)(NSArray *, NSError *))completion;
+                      unit:(HKUnit *)unit;
 
 
 - (void)fetchQuantitySamplesOfType:(HKQuantityType *)quantityType
diff --git a/RCTAppleHealthKit/RCTAppleHealthKit+Queries.m b/RCTAppleHealthKit/RCTAppleHealthKit+Queries.m
index d84600ae890125f345b21d17dbff477e1e7d345b..7e73b656eb1015aa02c2a12a583e0a7ee3811b9c 100644
--- a/RCTAppleHealthKit/RCTAppleHealthKit+Queries.m
+++ b/RCTAppleHealthKit/RCTAppleHealthKit+Queries.m
@@ -14,7 +14,6 @@
 
 @implementation RCTAppleHealthKit (Queries)
 
-
 - (void)fetchMostRecentQuantitySampleOfType:(HKQuantityType *)quantityType
                                   predicate:(NSPredicate *)predicate
                                  completion:(void (^)(HKQuantity *, NSDate *, NSDate *, NSError *))completion {
@@ -203,58 +202,25 @@
 }
 
 - (void)setObserverForType:(HKSampleType *)type
-                      unit:(HKUnit *)unit
-                completion:(void (^)(NSArray *, NSError *))completion {
+                      unit:(HKUnit *)unit {
     NSLog(@"set observer");
-    void(^handler)(HKObserverQuery *query, HKObserverQueryCompletionHandler completionHandler, NSError * _Nullable error);
-    handler = ^(HKObserverQuery *query, HKObserverQueryCompletionHandler completionHandler, NSError * _Nullable error) {
-        NSLog(@"enter to a handler %@", [error localizedDescription]);
+    HKObserverQuery *query = [[HKObserverQuery alloc] initWithSampleType:type predicate:nil updateHandler:^(HKObserverQuery *query, HKObserverQueryCompletionHandler completionHandler, NSError * _Nullable error){
         UIApplication *app = [UIApplication sharedApplication];
-        UIApplicationState appState = [app applicationState];
-
-        if (!self.isSync){
-//            switch (appState) {
-//            case UIApplicationStateActive:
-//                NSLog(@"app Active try to make sync");
-//                break;
-//            case UIApplicationStateInactive:
-//                {
-//                    NSLog(@"enter to inactive case");
-//                break;
-//                }
-//            case UIApplicationStateBackground:
-//                {
-//                    NSLog(@"enter to background case");
-//                    self.isSync = true;
-//                    __block UIBackgroundTaskIdentifier backgroundTaskIdentifier = [app beginBackgroundTaskWithExpirationHandler:^{
+        NSLog(@"observer fired");
+        [self.bridge.eventDispatcher sendAppEventWithName:@"observer"             body:@""];
+        completionHandler();
+//        self.isSync = true;
+//        __block UIBackgroundTaskIdentifier backgroundTaskIdentifier = [app beginBackgroundTaskWithExpirationHandler:^{
 //
-//                        NSLog(@"call event background");
-////                        [self.bridge.eventDispatcher sendAppEventWithName:@"change:steps"
-////                                                                     body:@{@"name": @"change:steps"}];
-//                        [self fetchSamplesOfType:type unit:unit predicate:nil ascending:true limit:1 completion:completion];
-//                        [app endBackgroundTask:backgroundTaskIdentifier];
-//                        self.isSync = false;
-//                    }];
-//                }
+//            NSLog(@"observer fired from bg");
+//            [self.bridge.eventDispatcher sendAppEventWithName:@"observer"
+//                                                         body:@""];
 //
-//            };
-            
-            NSLog(@"enter to background case");
-            self.isSync = true;
-            __block UIBackgroundTaskIdentifier backgroundTaskIdentifier = [app beginBackgroundTaskWithExpirationHandler:^{
-                
-                NSLog(@"call event background");
-                                        [self.bridge.eventDispatcher sendAppEventWithName:@"change:steps"
-                                                                                     body:@{@"name": @"change:steps"}];
-                [self fetchSamplesOfType:type unit:unit predicate:nil ascending:true limit:1 completion:completion];
-                [app endBackgroundTask:backgroundTaskIdentifier];
-                completionHandler();
-                self.isSync = false;
-            }];
-        }
-        
-    };
-    HKObserverQuery *query = [[HKObserverQuery alloc] initWithSampleType:type predicate:nil updateHandler:handler];
+//            [app endBackgroundTask:backgroundTaskIdentifier];
+//            completionHandler();
+//            self.isSync = false;
+//        }];
+    }];
     
     [self.healthStore executeQuery:query];
     [self.healthStore enableBackgroundDeliveryForType:type frequency:HKUpdateFrequencyImmediate withCompletion:^(BOOL success, NSError * _Nullable error) {
@@ -262,9 +228,6 @@
     }];
 }
 
-
-
-
 - (void)fetchSleepCategorySamplesForPredicate:(NSPredicate *)predicate
                                    limit:(NSUInteger)lim
                                    completion:(void (^)(NSArray *, NSError *))completion {
diff --git a/RCTAppleHealthKit/RCTAppleHealthKit.m b/RCTAppleHealthKit/RCTAppleHealthKit.m
index 2d1fa49eb646e715a9a8053188273760da144c1e..bbc9c171fecf79d630933c2c64345d1bd81e5d43 100644
--- a/RCTAppleHealthKit/RCTAppleHealthKit.m
+++ b/RCTAppleHealthKit/RCTAppleHealthKit.m
@@ -111,9 +111,9 @@ RCT_EXPORT_METHOD(getSamples:(NSDictionary *)input callback:(RCTResponseSenderBl
     [self fitness_getSamples:input callback:callback];
 }
 
-RCT_EXPORT_METHOD(setObserver:(NSDictionary *)input callback:(RCTResponseSenderBlock)callback)
+RCT_EXPORT_METHOD(setObserver:(NSDictionary *)input)
 {
-    [self fitness_setObserver:input callback:callback];
+    [self fitness_setObserver:input];
 }