diff --git a/src/Common/EncryptionThreadPool.c b/src/Common/EncryptionThreadPool.c
index 6124497d..50e33c7f 100644
--- a/src/Common/EncryptionThreadPool.c
+++ b/src/Common/EncryptionThreadPool.c
@@ -192,6 +192,7 @@ static void SetWorkItemState (EncryptionThreadPoolWorkItem *workItem, WorkItemSt
 static TC_THREAD_PROC EncryptionThreadProc (void *threadArg)
 {
 	EncryptionThreadPoolWorkItem *workItem;
+	EncryptionThreadPoolWorkItem *firstFragment;
 	if (threadArg)
 	{
 #ifdef DEVICE_DRIVER
@@ -333,14 +334,16 @@ static TC_THREAD_PROC EncryptionThreadProc (void *threadArg)
 			TC_THROW_FATAL_EXCEPTION;
 		}
 
-		if (workItem != workItem->FirstFragment)
+		// Keep the parent reference before releasing this queue slot.
+		firstFragment = workItem->FirstFragment;
+		if (workItem != firstFragment)
 		{
 			SetWorkItemState (workItem, WorkItemFree);
 			TC_SET_EVENT (WorkItemCompletedEvent);
 		}
 
-		if (InterlockedDecrement (&workItem->FirstFragment->OutstandingFragmentCount) == 0)
-			TC_SET_EVENT (workItem->FirstFragment->ItemCompletedEvent);
+		if (InterlockedDecrement (&firstFragment->OutstandingFragmentCount) == 0)
+			TC_SET_EVENT (firstFragment->ItemCompletedEvent);
 	}
 
 #ifdef DEVICE_DRIVER
diff --git a/src/Volume/EncryptionThreadPool.cpp b/src/Volume/EncryptionThreadPool.cpp
index a7f4a4ce..0b37df0f 100644
--- a/src/Volume/EncryptionThreadPool.cpp
+++ b/src/Volume/EncryptionThreadPool.cpp
@@ -375,14 +375,16 @@ namespace VeraCrypt
 					continue;
 				}
 
-				if (workItem != workItem->FirstFragment)
+				// Keep the parent reference before releasing this queue slot.
+				WorkItem *firstFragment = workItem->FirstFragment;
+				if (workItem != firstFragment)
 				{
 					workItem->State.Set (WorkItem::State::Free);
 					WorkItemCompletedEvent.Signal();
 				}
 
-				if (workItem->FirstFragment->OutstandingFragmentCount.Decrement() == 0)
-					workItem->FirstFragment->ItemCompletedEvent.Signal();
+				if (firstFragment->OutstandingFragmentCount.Decrement() == 0)
+					firstFragment->ItemCompletedEvent.Signal();
 			}
 		}
 		catch (exception &e)