diff --git a/MQTTClient.podspec b/MQTTClient.podspec
index 4b2a9b3d..317f6650 100644
--- a/MQTTClient.podspec
+++ b/MQTTClient.podspec
@@ -1,13 +1,13 @@
 Pod::Spec.new do |mqttc|
 	mqttc.name         = "MQTTClient"
-	mqttc.version      = "0.7.4"
+	mqttc.version      = "0.7.5"
 	mqttc.summary      = "iOS, OSX and tvOS native ObjectiveC MQTT Client Framework"
 	mqttc.homepage     = "https://github.com/ckrey/MQTT-Client-Framework"
 	mqttc.license      = { :type => "EPLv1", :file => "LICENSE" }
 	mqttc.author       = { "Christoph Krey" => "krey.christoph@gmail.com" }
 	mqttc.source       = {
 		:git => "https://github.com/ckrey/MQTT-Client-Framework.git",
-		:tag => "0.7.4",
+		:tag => "0.7.5",
 		:submodules => true
 	}
 
diff --git a/MQTTClient/MQTTClient/MQTTCoreDataPersistence.m b/MQTTClient/MQTTClient/MQTTCoreDataPersistence.m
index 9d45e357..b3b5591e 100755
--- a/MQTTClient/MQTTClient/MQTTCoreDataPersistence.m
+++ b/MQTTClient/MQTTClient/MQTTCoreDataPersistence.m
@@ -162,28 +162,6 @@ - (void)setDeadline:(NSDate *)deadline {
 
 @end
 
-// Attempt to fix #117
-//
-//@interface NSManagedObjectContext ( Recursive )
-//- (void)recursiveSave;
-//@end
-//
-//@implementation NSManagedObjectContext ( Recursive )
-//
-//- (void)recursiveSave {
-//    if (self.hasChanges) {
-//        NSError *error = nil;
-//        if (![self save: &error]) {
-//            DDLogError(@"[MQTTPersistence] sync error %@", error);
-//        }
-//        
-//        if (self.parentContext) {
-//            [self.parentContext recursiveSave];
-//        }
-//    }
-//}
-//@end
-//
 @implementation MQTTCoreDataPersistence
 @synthesize persistent;
 @synthesize maxSize;
@@ -260,28 +238,52 @@ - (void)deleteAllFlowsForClientId:(NSString *)clientId {
 }
 
 - (void)sync {
-    [self.managedObjectContext performBlockAndWait:^{
+    if ([NSThread isMainThread]) {
+        [self internalSync];
+    } else {
+        [self.managedObjectContext performBlockAndWait:^{
+            [self internalSync];
+        }];
+    }
+    if ([NSThread isMainThread]) {
+        [self internalParentSync];
+    } else {
+        [self.managedObjectContext.parentContext performBlockAndWait:^{
+            [self internalParentSync];
+        }];
+    }
+}
+
+- (void)internalSync {
+    if (self.managedObjectContext.hasChanges) {
+        DDLogVerbose(@"[MQTTPersistence] pre-sync: i%lu u%lu d%lu",
+                     (unsigned long)self.managedObjectContext.insertedObjects.count,
+                     (unsigned long)self.managedObjectContext.updatedObjects.count,
+                     (unsigned long)self.managedObjectContext.deletedObjects.count
+                     );
+        NSError *error = nil;
+        if (![self.managedObjectContext save:&error]) {
+            DDLogError(@"[MQTTPersistence] sync error %@", error);
+        }
         if (self.managedObjectContext.hasChanges) {
-            DDLogVerbose(@"[MQTTPersistence] pre-sync: i%lu u%lu d%lu",
-                         (unsigned long)self.managedObjectContext.insertedObjects.count,
-                         (unsigned long)self.managedObjectContext.updatedObjects.count,
-                         (unsigned long)self.managedObjectContext.deletedObjects.count
-                         );
-            NSError *error = nil;
-            if (![self.managedObjectContext save:&error]) {
-                DDLogError(@"[MQTTPersistence] sync error %@", error);
-            }
-            if (self.managedObjectContext.hasChanges) {
-                DDLogError(@"[MQTTPersistence] sync not complete");
-            }
-            DDLogVerbose(@"[MQTTPersistence] postsync: i%lu u%lu d%lu",
-                         (unsigned long)self.managedObjectContext.insertedObjects.count,
-                         (unsigned long)self.managedObjectContext.updatedObjects.count,
-                         (unsigned long)self.managedObjectContext.deletedObjects.count
-                         );
-            [self sizes];
+            DDLogError(@"[MQTTPersistence] sync not complete");
         }
-    }];
+        DDLogVerbose(@"[MQTTPersistence] postsync: i%lu u%lu d%lu",
+                     (unsigned long)self.managedObjectContext.insertedObjects.count,
+                     (unsigned long)self.managedObjectContext.updatedObjects.count,
+                     (unsigned long)self.managedObjectContext.deletedObjects.count
+                     );
+        [self sizes];
+    }
+}
+
+- (void)internalParentSync {
+    if (self.managedObjectContext.parentContext && self.managedObjectContext.parentContext.hasChanges) {
+        NSError *error = nil;
+        if (![self.managedObjectContext.parentContext save:&error]) {
+            DDLogError(@"[MQTTPersistence] parentContext sync error %@", error);
+        }
+    }
 }
 
 - (NSArray *)allFlowsforClientId:(NSString *)clientId
diff --git a/MQTTClient/MQTTClientTests/MQTTClientPublishTests.m b/MQTTClient/MQTTClientTests/MQTTClientPublishTests.m
index 73fbbfc8..078b6ee1 100644
--- a/MQTTClient/MQTTClientTests/MQTTClientPublishTests.m
+++ b/MQTTClient/MQTTClientTests/MQTTClientPublishTests.m
@@ -63,6 +63,27 @@ - (void)testPublish_r0_q0_zeroLengthPayload {
     }
 }
 
+- (void)testPublish_r1_q0_zeroLengthPayload {
+    for (NSString *broker in self.brokers.allKeys) {
+        DDLogVerbose(@"testing broker %@", broker);
+        NSDictionary *parameters = self.brokers[broker];
+        [self connect:parameters];
+        [self testPublish:[[NSData alloc] init]
+                  onTopic:[NSString stringWithFormat:@"%@/%s", TOPIC, __FUNCTION__]
+                   retain:TRUE
+                  atLevel:0];
+        [self testPublish:[@"data" dataUsingEncoding:NSUTF8StringEncoding]
+                  onTopic:[NSString stringWithFormat:@"%@/%s", TOPIC, __FUNCTION__]
+                   retain:TRUE
+                  atLevel:0];
+        [self testPublish:[[NSData alloc] init]
+                  onTopic:[NSString stringWithFormat:@"%@/%s", TOPIC, __FUNCTION__]
+                   retain:TRUE
+                  atLevel:0];
+        [self shutdown:parameters];
+    }
+}
+
 - (void)testPublish_r0_q0 {
     for (NSString *broker in self.brokers.allKeys) {
         DDLogVerbose(@"testing broker %@", broker);
diff --git a/MQTTClient/MQTTClientTests/MQTTTestHelpers.plist b/MQTTClient/MQTTClientTests/MQTTTestHelpers.plist
index 17da2387..31681d8c 100644
--- a/MQTTClient/MQTTClientTests/MQTTTestHelpers.plist
+++ b/MQTTClient/MQTTClientTests/MQTTTestHelpers.plist
@@ -44,6 +44,10 @@
 			<false/>
 			<key>allowUntrustedCertificates</key>
 			<false/>
+			<key>CoreData</key>
+			<true/>
+			<key>persistent</key>
+			<true/>
 		</dict>
 		<key>localWS</key>
 		<dict>