diff --git a/iphone/Maps/Classes/CustomViews/Login/MWMAuthorizationCommon.mm b/iphone/Maps/Classes/CustomViews/Login/MWMAuthorizationCommon.mm
index 356b8aa0ab..f22c42d6d9 100644
--- a/iphone/Maps/Classes/CustomViews/Login/MWMAuthorizationCommon.mm
+++ b/iphone/Maps/Classes/CustomViews/Login/MWMAuthorizationCommon.mm
@@ -44,7 +44,6 @@ void AuthorizationStoreCredentials(std::string const & oauthToken)
     // To also see # of edits when offline.
     [ud setInteger:prefs.m_changesets forKey:kOSMChangesetsCount];
   }
-  [ud synchronize];
 }
 
 BOOL AuthorizationHaveOAuth1Credentials()
@@ -60,7 +59,6 @@ void AuthorizationClearOAuth1Credentials()
   NSUserDefaults * ud = NSUserDefaults.standardUserDefaults;
   [ud removeObjectForKey:kOSMRequestToken];
   [ud removeObjectForKey:kOSMRequestSecret];
-  [ud synchronize];
 }
 
 BOOL AuthorizationHaveCredentials()
@@ -78,7 +76,6 @@ void AuthorizationClearCredentials()
   [ud removeObjectForKey:kOSMRequestSecret];
   [ud removeObjectForKey:kOSMUserName];
   [ud removeObjectForKey:kOSMChangesetsCount];
-  [ud synchronize];
 }
 
 std::string const AuthorizationGetCredentials()
@@ -94,7 +91,6 @@ void AuthorizationSetNeedCheck(BOOL needCheck)
 {
   NSUserDefaults * ud = NSUserDefaults.standardUserDefaults;
   [ud setBool:needCheck forKey:kAuthNeedCheck];
-  [ud synchronize];
 }
 
 BOOL AuthorizationIsNeedCheck()
@@ -120,7 +116,6 @@ NSInteger OSMUserChangesetsCount()
   if (count >= 0)
   {
     [ud setInteger:count forKey:kOSMChangesetsCount];
-    [ud synchronize];
     return count;
   }
   return [ud integerForKey:kOSMChangesetsCount];
diff --git a/iphone/Maps/Classes/FirstSession.mm b/iphone/Maps/Classes/FirstSession.mm
index 3532ffdddd..6ea496b06a 100644
--- a/iphone/Maps/Classes/FirstSession.mm
+++ b/iphone/Maps/Classes/FirstSession.mm
@@ -99,7 +99,6 @@ static NSString * gInstallationId = nil;
     // Non-standard situation: this method is called before calling setup. Return current date.
     date = [NSDate date];
     [ud setObject:date forKey:kFirstLaunchDateKey];
-    [ud synchronize];
   }
   return date;
 }
@@ -142,7 +141,6 @@ static NSString * gInstallationId = nil;
       gInstallationId = [@"I:" stringByAppendingString:(NSString *)CFBridgingRelease(CFUUIDCreateString(kCFAllocatorDefault, uuid))];
       CFRelease(uuid);
       [ud setValue:gInstallationId forKey:kAlohalyticsInstallationId];
-      [ud synchronize];
       gIsFirstSession = YES;
     }
   }
diff --git a/iphone/Maps/Classes/MapViewController.mm b/iphone/Maps/Classes/MapViewController.mm
index cf82f0bce2..3dc8bfece8 100644
--- a/iphone/Maps/Classes/MapViewController.mm
+++ b/iphone/Maps/Classes/MapViewController.mm
@@ -397,7 +397,6 @@ NSString *const kPP2BookmarkEditingSegue = @"PP2BookmarkEditing";
   [self.alertController presentEditorViralAlert];
 
   [ud setObject:[NSDate date] forKey:kUDViralAlertWasShown];
-  [ud synchronize];
 }
 
 - (void)viewWillDisappear:(BOOL)animated {
diff --git a/iphone/Maps/Classes/MapsAppDelegate.mm b/iphone/Maps/Classes/MapsAppDelegate.mm
index bab49ac79a..e3c3b8927f 100644
--- a/iphone/Maps/Classes/MapsAppDelegate.mm
+++ b/iphone/Maps/Classes/MapsAppDelegate.mm
@@ -375,7 +375,6 @@ using namespace osm_auth_ios;
   [standartDefaults setObject:currentVersion forKey:kUDFirstVersionKey];
   [standartDefaults setInteger:1 forKey:kUDSessionsCountKey];
   [standartDefaults setObject:NSDate.date forKey:kUDLastLaunchDateKey];
-  [standartDefaults synchronize];
 }
 
 - (void)incrementSessionCount {
@@ -390,7 +389,6 @@ using namespace osm_auth_ios;
     sessionCount++;
     [standartDefaults setInteger:sessionCount forKey:kUDSessionsCountKey];
     [standartDefaults setObject:NSDate.date forKey:kUDLastLaunchDateKey];
-    [standartDefaults synchronize];
   }
 }
 
diff --git a/iphone/Maps/Core/Location/MWMLocationManager.mm b/iphone/Maps/Core/Location/MWMLocationManager.mm
index b18e9ed5fc..a0f50ddddd 100644
--- a/iphone/Maps/Core/Location/MWMLocationManager.mm
+++ b/iphone/Maps/Core/Location/MWMLocationManager.mm
@@ -102,7 +102,6 @@ BOOL needShowLocationAlert() {
 void setShowLocationAlert(BOOL needShow) {
   NSUserDefaults * ud = NSUserDefaults.standardUserDefaults;
   [ud setBool:needShow forKey:kLocationAlertNeedShowKey];
-  [ud synchronize];
 }
 }  // namespace
 
diff --git a/iphone/Maps/Core/Settings/MWMSettings.mm b/iphone/Maps/Core/Settings/MWMSettings.mm
index d999bf3289..e42547b347 100644
--- a/iphone/Maps/Core/Settings/MWMSettings.mm
+++ b/iphone/Maps/Core/Settings/MWMSettings.mm
@@ -116,7 +116,6 @@ NSString * const kUDTrackWarningAlertWasShown = @"TrackWarningAlertWasShown";
 {
   NSUserDefaults * ud = NSUserDefaults.standardUserDefaults;
   [ud setObject:spotlightLocaleLanguageId forKey:kSpotlightLocaleLanguageId];
-  [ud synchronize];
 }
 
 + (BOOL)largeFontSize { return GetFramework().LoadLargeFontsSize(); }
@@ -143,7 +142,6 @@ NSString * const kUDTrackWarningAlertWasShown = @"TrackWarningAlertWasShown";
 {
   NSUserDefaults * ud = NSUserDefaults.standardUserDefaults;
   [ud setBool:shown forKey:kUDTrackWarningAlertWasShown];
-  [ud synchronize];
 }
 
 + (NSString *)donateUrl
diff --git a/iphone/Maps/Core/TextToSpeech/MWMTextToSpeech.mm b/iphone/Maps/Core/TextToSpeech/MWMTextToSpeech.mm
index 9405202a28..f16bc4775b 100644
--- a/iphone/Maps/Core/TextToSpeech/MWMTextToSpeech.mm
+++ b/iphone/Maps/Core/TextToSpeech/MWMTextToSpeech.mm
@@ -121,7 +121,6 @@ using Observers = NSHashTable<Observer>;
 - (void)setNotificationsLocale:(NSString *)locale {
   NSUserDefaults * ud = NSUserDefaults.standardUserDefaults;
   [ud setObject:locale forKey:kUserDefaultsTTSLanguageBcp47];
-  [ud synchronize];
   [self createVoice:locale];
 }
 
@@ -135,7 +134,6 @@ using Observers = NSHashTable<Observer>;
     [tts setActive:NO];
   NSUserDefaults * ud = NSUserDefaults.standardUserDefaults;
   [ud setBool:enabled forKey:kIsTTSEnabled];
-  [ud synchronize];
 
   [tts onTTSStatusUpdated];
   if (enabled)
diff --git a/iphone/Maps/UI/Editor/MWMEditorViewController.mm b/iphone/Maps/UI/Editor/MWMEditorViewController.mm
index eb3c8fdedd..55411c64e5 100644
--- a/iphone/Maps/UI/Editor/MWMEditorViewController.mm
+++ b/iphone/Maps/UI/Editor/MWMEditorViewController.mm
@@ -1086,7 +1086,6 @@ void registerCellsForTableView(std::vector<MWMEditorCellID> const & cells, UITab
   [self.alertController presentPersonalInfoWarningAlertWithBlock:^
   {
     [ud setBool:YES forKey:kUDEditorPersonalInfoWarninWasShown];
-    [ud synchronize];
     [self onSave];
   }];