diff --git a/Source/AFMMRecordResponseSerializer/AFMMRecordResponseSerializer.m b/Source/AFMMRecordResponseSerializer/AFMMRecordResponseSerializer.m
index a454881..03f5c2a 100644
--- a/Source/AFMMRecordResponseSerializer/AFMMRecordResponseSerializer.m
+++ b/Source/AFMMRecordResponseSerializer/AFMMRecordResponseSerializer.m
@@ -107,11 +107,23 @@ - (NSManagedObjectContext *)backgroundContext {
 }
 
 - (NSArray *)recordsFromMMRecordResponse:(MMRecordResponse *)recordResponse
-                       backgroundContext:(NSManagedObjectContext *)backgroundContext {
-    __block NSMutableArray *objectIDs = [NSMutableArray array];
+                       backgroundContext:(NSManagedObjectContext *)backgroundContext
+                                 options:(MMRecordOptions *)options {
+    NSMutableArray *objectIDs = [NSMutableArray array];
     
     [backgroundContext performBlockAndWait:^{
+        NSError *error;
         NSArray *records = [recordResponse records];
+        if (![backgroundContext save:&error]) {
+            NSDictionary *parameters = nil;
+            if (error.localizedDescription != nil) {
+                parameters = [options.debugger parametersWithKeys:@[MMRecordDebuggerParameterErrorDescription]
+                                              values:@[error.localizedDescription]];
+            }
+            [options.debugger handleErrorCode:MMRecordErrorCodeCoreDataSaveError
+                               withParameters:parameters];
+            return;
+        }
         
         for (MMRecord *record in records) {
             [objectIDs addObject:[record objectID]];
@@ -120,9 +132,11 @@ - (NSArray *)recordsFromMMRecordResponse:(MMRecordResponse *)recordResponse
     
     NSMutableArray *records = [NSMutableArray array];
     
-    for (NSManagedObjectID *objectID in objectIDs) {
-        [records addObject:[self.context objectWithID:objectID]];
-    }
+    [self.context performBlockAndWait:^{
+        for (NSManagedObjectID *objectID in objectIDs) {
+            [records addObject:[self.context objectWithID:objectID]];
+        }
+    }];
     
     return records;
 }
@@ -186,11 +200,12 @@ - (id)responseObjectForResponse:(NSURLResponse *)response
     
     MMRecordResponse *recordResponse = [MMRecordResponse responseFromResponseObjectArray:responseArray
                                                                            initialEntity:initialEntity
-                                                                                 context:self.context
+                                                                                 context:backgroundContext
                                                                                  options:options];
     
     NSArray *records = [self recordsFromMMRecordResponse:recordResponse
-                                       backgroundContext:backgroundContext];
+                                       backgroundContext:backgroundContext
+                                                 options:options];
     
     *error = [debugger primaryError];
     
diff --git a/Source/MMRecord/MMRecordProtoRecord.h b/Source/MMRecord/MMRecordProtoRecord.h
index 7428869..b31e1a7 100644
--- a/Source/MMRecord/MMRecordProtoRecord.h
+++ b/Source/MMRecord/MMRecordProtoRecord.h
@@ -132,7 +132,8 @@
  */
 + (MMRecordProtoRecord *)protoRecordWithDictionary:(NSDictionary *)dictionary
                                             entity:(NSEntityDescription *)entity
-                                    representation:(MMRecordRepresentation *)representation;
+                                    representation:(MMRecordRepresentation *)representation
+                                   primaryKeyValue:(id)primaryKeyValue;
 
 
 ///---------------------------
diff --git a/Source/MMRecord/MMRecordProtoRecord.m b/Source/MMRecord/MMRecordProtoRecord.m
index e6c5927..b1fa2fb 100644
--- a/Source/MMRecord/MMRecordProtoRecord.m
+++ b/Source/MMRecord/MMRecordProtoRecord.m
@@ -39,12 +39,13 @@ @implementation MMRecordProtoRecord
 
 + (MMRecordProtoRecord *)protoRecordWithDictionary:(NSDictionary *)dictionary
                                             entity:(NSEntityDescription *)entity
-                                    representation:(MMRecordRepresentation *)representation {
+                                    representation:(MMRecordRepresentation *)representation
+                                   primaryKeyValue:(id)primaryKeyValue {
     NSParameterAssert([NSClassFromString([entity managedObjectClassName]) isSubclassOfClass:[MMRecord class]]);
     MMRecordProtoRecord *protoRecord = [[MMRecordProtoRecord alloc] init];
     protoRecord.dictionary = dictionary;
     protoRecord.entity = entity;
-    protoRecord.primaryKeyValue = [representation primaryKeyValueFromDictionary:dictionary];
+    protoRecord.primaryKeyValue = primaryKeyValue;
     protoRecord.relationshipProtosDictionary = [NSMutableDictionary dictionary];
     protoRecord.relationshipDescriptionsDictionary = [NSMutableDictionary dictionary];
     protoRecord.hasRelationshipPrimarykey = [representation hasRelationshipPrimaryKey];
diff --git a/Source/MMRecord/MMRecordResponse.m b/Source/MMRecord/MMRecordResponse.m
index 367928f..064155d 100644
--- a/Source/MMRecord/MMRecordResponse.m
+++ b/Source/MMRecord/MMRecordResponse.m
@@ -223,35 +223,32 @@ - (MMRecordProtoRecord *)protoRecordWithRecordResponseObject:(id)recordResponseO
     }
     
     id primaryValue = [representation primaryKeyValueFromDictionary:recordResponseObject];
-    MMRecordProtoRecord *proto = [recordResponseGroup protoRecordForPrimaryKeyValue:primaryValue];
-    
-    if (proto == nil) {
-        proto = [MMRecordProtoRecord protoRecordWithDictionary:recordResponseObject
-                                                        entity:entity
-                                                representation:representation];
-        
-        
-        if (proto.hasRelationshipPrimarykey == NO) {
-            if (proto.primaryKeyValue == nil) {
-                if (self.options.entityPrimaryKeyInjectionBlock != nil) {
-                    proto.primaryKeyValue = self.options.entityPrimaryKeyInjectionBlock(proto.entity,
-                                                                                        proto.dictionary,
-                                                                                        parentProtoRecord);
-                }
-            }
-            
-            if (proto.primaryKeyValue == nil) {
+    if (primaryValue == nil) {
+        if (self.options.entityPrimaryKeyInjectionBlock != nil) {
+            primaryValue = self.options.entityPrimaryKeyInjectionBlock(entity,
+                                                                       recordResponseObject,
+                                                                       parentProtoRecord);
+            if (primaryValue == nil) {
                 MMRecordDebugger *debugger = self.options.debugger;
-                NSString *errorDescription = [NSString stringWithFormat:@"Creating proto record with no primary key value. \"%@\"", proto];
+                NSString *errorDescription = [NSString stringWithFormat:@"No primary key value for response object. \"%@\"", recordResponseObject];
                 NSDictionary *parameters = [debugger parametersWithKeys:@[MMRecordDebuggerParameterRecordClassName,
                                                                           MMRecordDebuggerParameterErrorDescription,
                                                                           MMRecordDebuggerParameterEntityDescription]
-                                                                 values:@[proto.entity.managedObjectClassName,
+                                                                 values:@[entity.managedObjectClassName,
                                                                           errorDescription,
-                                                                          proto.entity]];
+                                                                          entity]];
                 [debugger handleErrorCode:MMRecordErrorCodeMissingRecordPrimaryKey withParameters:parameters];
             }
         }
+    }
+    MMRecordProtoRecord *proto = [recordResponseGroup protoRecordForPrimaryKeyValue:primaryValue];    
+    
+    if (proto == nil) {
+        proto = [MMRecordProtoRecord protoRecordWithDictionary:recordResponseObject
+                                                        entity:entity
+                                                representation:representation
+                                               primaryKeyValue:primaryValue];
+        
     } else {
         [representation.marshalerClass mergeDuplicateRecordResponseObjectDictionary:recordResponseObject
                                                             withExistingProtoRecord:proto];