diff --git a/src/sys/create.c b/src/sys/create.c
index 9ecfa68e..18cd264f 100644
--- a/src/sys/create.c
+++ b/src/sys/create.c
@@ -238,10 +238,6 @@ static NTSTATUS FspFsvolCreateNoLock(
 
         FileName.Length = (USHORT)
             ((PUINT8)StreamPart.Buffer - (PUINT8)FileName.Buffer + StreamPart.Length);
-
-        MainFileName.Length = MainFileName.MaximumLength = (USHORT)
-            ((PUINT8)StreamPart.Buffer - (PUINT8)FileName.Buffer - sizeof(WCHAR));
-        MainFileName.Buffer = FileName.Buffer;
     }
 
     /* is this a relative or absolute open? */
@@ -381,7 +377,13 @@ static NTSTATUS FspFsvolCreateNoLock(
             goto main_stream_exit;
         }
 
-        Result = FspMainFileOpen(FsvolDeviceObject,
+        MainFileName.Length = MainFileName.MaximumLength = (USHORT)
+            ((PUINT8)StreamPart.Buffer - (PUINT8)FileName.Buffer - sizeof(WCHAR));
+        MainFileName.Buffer = FileName.Buffer;
+
+        Result = FspMainFileOpen(
+            FsvolDeviceObject,
+            FileObject->DeviceObject, /* use as device hint when using MUP */
             &MainFileName, CaseSensitive,
             SecurityDescriptor,
             FileAttributes,
@@ -406,9 +408,6 @@ static NTSTATUS FspFsvolCreateNoLock(
         /* remember the main file node */
         FileNode->MainFileNode = FileDesc->MainFileObject->FsContext;
 
-        ASSERT(RtlEqualUnicodeString(&MainFileName, &FileNode->MainFileNode->FileName,
-            !CaseSensitive));
-
         Result = STATUS_SUCCESS;
 
     main_stream_exit:
diff --git a/src/sys/driver.h b/src/sys/driver.h
index 17e611a4..40da8934 100644
--- a/src/sys/driver.h
+++ b/src/sys/driver.h
@@ -1025,6 +1025,7 @@ NTSTATUS FspFileDescResetDirectoryPattern(FSP_FILE_DESC *FileDesc,
     PUNICODE_STRING FileName, BOOLEAN Reset);
 NTSTATUS FspMainFileOpen(
     PDEVICE_OBJECT FsvolDeviceObject,
+    PDEVICE_OBJECT DeviceObjectHint,
     PUNICODE_STRING MainFileName, BOOLEAN CaseSensitive,
     PSECURITY_DESCRIPTOR SecurityDescriptor,
     ULONG FileAttributes,
diff --git a/src/sys/file.c b/src/sys/file.c
index 094e7512..8470614a 100644
--- a/src/sys/file.c
+++ b/src/sys/file.c
@@ -72,6 +72,7 @@ NTSTATUS FspFileDescResetDirectoryPattern(FSP_FILE_DESC *FileDesc,
     PUNICODE_STRING FileName, BOOLEAN Reset);
 NTSTATUS FspMainFileOpen(
     PDEVICE_OBJECT FsvolDeviceObject,
+    PDEVICE_OBJECT DeviceObjectHint,
     PUNICODE_STRING MainFileName, BOOLEAN CaseSensitive,
     PSECURITY_DESCRIPTOR SecurityDescriptor,
     ULONG FileAttributes,
@@ -1253,6 +1254,7 @@ NTSTATUS FspFileDescResetDirectoryPattern(FSP_FILE_DESC *FileDesc,
 
 NTSTATUS FspMainFileOpen(
     PDEVICE_OBJECT FsvolDeviceObject,
+    PDEVICE_OBJECT DeviceObjectHint,
     PUNICODE_STRING MainFileName, BOOLEAN CaseSensitive,
     PSECURITY_DESCRIPTOR SecurityDescriptor,
     ULONG FileAttributes,
@@ -1297,7 +1299,6 @@ NTSTATUS FspMainFileOpen(
     FullFileName.Length = 0;
     FullFileName.MaximumLength =
         FsvolDeviceExtension->VolumeName.Length +
-        FsvolDeviceExtension->VolumePrefix.Length +
         MainFileName->Length;
     FullFileName.Buffer = FspAlloc(FullFileName.MaximumLength);
     if (0 == FullFileName.Buffer)
@@ -1307,7 +1308,6 @@ NTSTATUS FspMainFileOpen(
     }
 
     RtlAppendUnicodeStringToString(&FullFileName, &FsvolDeviceExtension->VolumeName);
-    RtlAppendUnicodeStringToString(&FullFileName, &FsvolDeviceExtension->VolumePrefix);
     RtlAppendUnicodeStringToString(&FullFileName, MainFileName);
 
     InitializeObjectAttributes(
@@ -1321,7 +1321,8 @@ NTSTATUS FspMainFileOpen(
     DriverCreateContext.Size =
         FIELD_OFFSET(IO_DRIVER_CREATE_CONTEXT, TxnParameters) +
         sizeof(((PIO_DRIVER_CREATE_CONTEXT)0)->TxnParameters);
-    DriverCreateContext.DeviceObjectHint = FsvolDeviceObject;
+    DriverCreateContext.DeviceObjectHint = 0 != FsvolDeviceExtension->FsvrtDeviceObject ?
+        FsvolDeviceObject : DeviceObjectHint;
 
     IoStatus.Status = FsRtlAllocateExtraCreateParameterList(0,
         &DriverCreateContext.ExtraCreateParameter);