diff --git a/opt/fsext/lib/winfsp-x64.lib b/opt/fsext/lib/winfsp-x64.lib
index a1192e27..9d30816f 100644
Binary files a/opt/fsext/lib/winfsp-x64.lib and b/opt/fsext/lib/winfsp-x64.lib differ
diff --git a/opt/fsext/lib/winfsp-x86.lib b/opt/fsext/lib/winfsp-x86.lib
index f34538f0..6616c9bb 100644
Binary files a/opt/fsext/lib/winfsp-x86.lib and b/opt/fsext/lib/winfsp-x86.lib differ
diff --git a/src/sys/device.c b/src/sys/device.c
index 321dcd6c..63cf14e0 100644
--- a/src/sys/device.c
+++ b/src/sys/device.c
@@ -329,7 +329,7 @@ static NTSTATUS FspFsvolDeviceInit(PDEVICE_OBJECT DeviceObject)
     if (0 != FsvolDeviceExtension->VolumeParams.FsextControlCode)
     {
         FSP_FSEXT_PROVIDER *Provider = FspFsextProvider(
-            FsvolDeviceExtension->VolumeParams.FsextControlCode, &Result);
+            FsvolDeviceExtension->VolumeParams.FsextControlCode, 0);
         if (0 != Provider)
         {
             Result = Provider->DeviceInit(DeviceObject, &FsvolDeviceExtension->VolumeParams);
@@ -338,10 +338,7 @@ static NTSTATUS FspFsvolDeviceInit(PDEVICE_OBJECT DeviceObject)
             FsvolDeviceExtension->InitDoneFsext = 1;
         }
         else
-        {
-            ASSERT(!NT_SUCCESS(Result));
-            return Result;
-        }
+            return STATUS_OBJECT_NAME_NOT_FOUND;
     }
 
     /* is there a virtual disk? */
diff --git a/src/sys/driver.h b/src/sys/driver.h
index ecf63697..73e20fd3 100644
--- a/src/sys/driver.h
+++ b/src/sys/driver.h
@@ -1188,7 +1188,7 @@ VOID FspDeviceGlobalUnlock(VOID)
     //    STATUS_VOLUME_DISMOUNTED : STATUS_DEVICE_NOT_CONNECTED)
 
 /* fsext */
-FSP_FSEXT_PROVIDER *FspFsextProvider(UINT32 ControlCode, PNTSTATUS PLoadResult);
+FSP_FSEXT_PROVIDER *FspFsextProvider(UINT32 FsextControlCode, PNTSTATUS PLoadResult);
 
 /* process buffers conditional usage */
 static inline
diff --git a/src/sys/fsext.c b/src/sys/fsext.c
index b11a428f..38272502 100644
--- a/src/sys/fsext.c
+++ b/src/sys/fsext.c
@@ -25,7 +25,7 @@
 static KSPIN_LOCK FsextSpinLock = 0;
 FSP_FSEXT_PROVIDER *FsextProvider;
 
-FSP_FSEXT_PROVIDER *FspFsextProvider(UINT32 ControlCode, PNTSTATUS PLoadResult)
+FSP_FSEXT_PROVIDER *FspFsextProvider(UINT32 FsextControlCode, PNTSTATUS PLoadResult)
 {
     FSP_FSEXT_PROVIDER *Provider;
     KIRQL Irql;
@@ -33,6 +33,8 @@ FSP_FSEXT_PROVIDER *FspFsextProvider(UINT32 ControlCode, PNTSTATUS PLoadResult)
     KeAcquireSpinLock(&FsextSpinLock, &Irql);
     Provider = FsextProvider;
     KeReleaseSpinLock(&FsextSpinLock, Irql);
+    if (0 != Provider && FsextControlCode != Provider->DeviceTransactCode)
+        Provider = 0;
 
     if (0 != PLoadResult)
     {
@@ -51,15 +53,12 @@ FSP_FSEXT_PROVIDER *FspFsextProvider(UINT32 ControlCode, PNTSTATUS PLoadResult)
 
             RtlInitUnicodeString(&Path, L"" FSP_REGKEY "\\Fsext");
             RtlInitEmptyUnicodeString(&Name, Buf, sizeof Buf);
-            Result = RtlUnicodeStringPrintf(&Name, L"%08x", ControlCode);
+            Result = RtlUnicodeStringPrintf(&Name, L"%08x", FsextControlCode);
             ASSERT(NT_SUCCESS(Result));
             Length = sizeof Value;
             Result = FspRegistryGetValue(&Path, &Name, &Value.V, &Length);
-            if (STATUS_SUCCESS != Result/*!NT_SUCCESS*/)
+            if (!NT_SUCCESS(Result))
             {
-                if (STATUS_BUFFER_OVERFLOW == Result)
-                    Result = STATUS_BUFFER_TOO_SMALL;
-
                 *PLoadResult = Result;
                 return 0;
             }
@@ -84,6 +83,8 @@ FSP_FSEXT_PROVIDER *FspFsextProvider(UINT32 ControlCode, PNTSTATUS PLoadResult)
             KeAcquireSpinLock(&FsextSpinLock, &Irql);
             Provider = FsextProvider;
             KeReleaseSpinLock(&FsextSpinLock, Irql);
+            if (0 != Provider && FsextControlCode != Provider->DeviceTransactCode)
+                Provider = 0;
         }
 
         *PLoadResult = 0 != Provider ? STATUS_SUCCESS : STATUS_OBJECT_NAME_NOT_FOUND;
diff --git a/src/sys/util.c b/src/sys/util.c
index 92ddcc04..1268f7cf 100644
--- a/src/sys/util.c
+++ b/src/sys/util.c
@@ -306,6 +306,7 @@ NTSTATUS FspRegistryGetValue(PUNICODE_STRING Path, PUNICODE_STRING ValueName,
         goto exit;
 
     Result = STATUS_SUCCESS;
+        /* NOTE: also converts STATUS_BUFFER_OVERFLOW to STATUS_SUCCESS */
 
 exit:
     if (0 != Handle)
diff --git a/src/sys/volume.c b/src/sys/volume.c
index 77792dba..7e9ae3b0 100644
--- a/src/sys/volume.c
+++ b/src/sys/volume.c
@@ -100,6 +100,7 @@ static NTSTATUS FspVolumeCreateNoLock(
     UNICODE_STRING VolumeName;
     UNICODE_STRING FsmupDeviceName;
     WCHAR VolumeNameBuf[FSP_FSCTL_VOLUME_NAME_SIZE / sizeof(WCHAR)];
+    FSP_FSEXT_PROVIDER *Provider = 0;
     PDEVICE_OBJECT FsvolDeviceObject;
     PDEVICE_OBJECT FsvrtDeviceObject;
     FSP_FSVOL_DEVICE_EXTENSION *FsvolDeviceExtension;
@@ -209,6 +210,14 @@ static NTSTATUS FspVolumeCreateNoLock(
     VolumeParams.AlwaysUseDoubleBuffering = 1;
 #endif
 
+    /* load any fsext provider */
+    if (0 != VolumeParams.FsextControlCode)
+    {
+        Provider = FspFsextProvider(VolumeParams.FsextControlCode, &Result);
+        if (0 == Provider)
+            return Result;
+    }
+
     /* create volume guid */
     Result = FspCreateGuid(&Guid);
     if (!NT_SUCCESS(Result))
@@ -226,7 +235,8 @@ static NTSTATUS FspVolumeCreateNoLock(
     VolumeName.MaximumLength = VolumeName.Length;
 
     /* create the volume (and virtual disk) device(s) */
-    Result = FspDeviceCreate(FspFsvolDeviceExtensionKind, 0,
+    Result = FspDeviceCreate(FspFsvolDeviceExtensionKind,
+        0 == Provider ? 0 : Provider->DeviceExtensionSize,
         FsctlDeviceObject->DeviceType,
         FILE_DEVICE_DISK_FILE_SYSTEM == FsctlDeviceObject->DeviceType ? 0 : FILE_REMOTE_DEVICE,
         &FsvolDeviceObject);
diff --git a/tools/impdef.bat b/tools/impdef.bat
index 60e13df5..8abbec83 100644
--- a/tools/impdef.bat
+++ b/tools/impdef.bat
@@ -10,7 +10,7 @@ set infile=%infile:/=\%
 set outfile=%2
 set outfile=%outfile:/=\%
 set workdir=!infile!.work
-set workbase=!workdir!\%~n1
+set workbase=!workdir!\%~n2
 set outarch=%~n2
 set outarch=%outarch:~-3%