diff --git a/Code/CoreData/RKManagedObjectMappingOperationDataSource.m b/Code/CoreData/RKManagedObjectMappingOperationDataSource.m
index d21069a5..ff2daab5 100644
--- a/Code/CoreData/RKManagedObjectMappingOperationDataSource.m
+++ b/Code/CoreData/RKManagedObjectMappingOperationDataSource.m
@@ -326,10 +326,15 @@ extern NSString * const RKObjectMappingNestingAttributeKeyName;
         // Delete the object immediately if there are no connections that may make it valid
         if ([connections count] == 0 && RKDeleteInvalidNewManagedObject(mappingOperation.destinationObject)) return YES;
         
-        // Attempt to establish the connections and delete the object if its invalid once we are done
+        /**
+         Attempt to establish the connections and delete the object if its invalid once we are done
+         
+         NOTE: We obtain a weak reference to the MOC to avoid a potential crash under iOS 5 if the MOC is deallocated before the operation executes. Under iOS 6, the object returns a nil `managedObjectContext` and the `performBlockAndWait:` message is sent to nil.
+         */
         NSOperationQueue *operationQueue = self.operationQueue ?: [NSOperationQueue currentQueue];
+        __weak NSManagedObjectContext *weakContext = [(NSManagedObject *)mappingOperation.destinationObject managedObjectContext];
         NSBlockOperation *deletionOperation = [NSBlockOperation blockOperationWithBlock:^{
-            [[(NSManagedObject *)mappingOperation.destinationObject managedObjectContext] performBlockAndWait:^{
+            [weakContext performBlockAndWait:^{
                 RKDeleteInvalidNewManagedObject(mappingOperation.destinationObject);
             }];
         }];
diff --git a/Tests/Logic/CoreData/RKManagedObjectMappingOperationDataSourceTest.m b/Tests/Logic/CoreData/RKManagedObjectMappingOperationDataSourceTest.m
index 69df82bc..7c86d5d3 100644
--- a/Tests/Logic/CoreData/RKManagedObjectMappingOperationDataSourceTest.m
+++ b/Tests/Logic/CoreData/RKManagedObjectMappingOperationDataSourceTest.m
@@ -1363,4 +1363,35 @@
     expect([blake valueForKey:@"favoriteCat"]).to.equal([mapper.mappingResult.dictionary objectForKey:@"cat"]);
 }
 
+- (void)testDeletionOperationAfterManagedObjectContextIsDeallocated
+{
+    RKManagedObjectStore *managedObjectStore = [RKTestFactory managedObjectStore];
+    NSManagedObjectContext *managedObjectContext = [managedObjectStore newChildManagedObjectContextWithConcurrencyType:NSPrivateQueueConcurrencyType];
+    RKManagedObjectMappingOperationDataSource *dataSource = [[RKManagedObjectMappingOperationDataSource alloc] initWithManagedObjectContext:managedObjectContext cache:nil];
+    
+    
+    NSDictionary *representation = @{ @"human": @{ @"name": @"Blake Watters", @"favoriteCatID": @(12345) }, @"cat": @{ @"railsID": @(12345) } };
+    RKEntityMapping *catMapping = [RKEntityMapping mappingForEntityForName:@"Cat"
+                                                      inManagedObjectStore:managedObjectStore];
+    RKCat *cat = [NSEntityDescription insertNewObjectForEntityForName:@"Cat" inManagedObjectContext:managedObjectContext];
+    RKMappingOperation *mappingOperation = [[RKMappingOperation alloc] initWithSourceObject:representation destinationObject:cat mapping:catMapping];
+    NSOperationQueue *operationQueue = [NSOperationQueue new];
+    [operationQueue setSuspended:YES];
+    dataSource.operationQueue = operationQueue;
+    
+    id mockOperation = [OCMockObject partialMockForObject:mappingOperation];
+    [[[mockOperation stub] andReturn:catMapping] objectMapping];
+    [dataSource commitChangesForMappingOperation:mockOperation error:nil];
+    
+    expect([operationQueue operationCount]).to.equal(1);
+    dataSource = nil;
+    managedObjectContext = nil;
+    [operationQueue setSuspended:NO];
+    
+    [operationQueue waitUntilAllOperationsAreFinished];
+    // Create a operation queue
+    // Create data source
+    
+}
+
 @end