diff --git a/drivers/filters/fltmgr/Volume.c b/drivers/filters/fltmgr/Volume.c
index d4c21bb9997..b448fd31156 100644
--- a/drivers/filters/fltmgr/Volume.c
+++ b/drivers/filters/fltmgr/Volume.c
@@ -179,5 +179,16 @@ FltEnumerateVolumes(
     return Status;
 }
 
+NTSTATUS
+FLTAPI
+FltDetachVolume(
+    _Inout_ PFLT_FILTER Filter,
+    _Inout_ PFLT_VOLUME Volume,
+    _In_opt_ PCUNICODE_STRING InstanceName)
+{
+    UNIMPLEMENTED;
+    return STATUS_NOT_IMPLEMENTED;
+}
+
 
 /* INTERNAL FUNCTIONS ******************************************************/
diff --git a/drivers/filters/fltmgr/fltmgr.spec b/drivers/filters/fltmgr/fltmgr.spec
index 3aae9326a0a..3bf66621c49 100644
--- a/drivers/filters/fltmgr/fltmgr.spec
+++ b/drivers/filters/fltmgr/fltmgr.spec
@@ -16,4 +16,5 @@
  @ stdcall FltClose(ptr)
  @ stdcall FltCreateFileEx(ptr ptr ptr ptr long ptr ptr ptr long long long long ptr long long)
  @ stdcall FltCreateFile(ptr ptr ptr long ptr ptr ptr long long long long ptr long long)
+ @ stdcall FltDetachVolume(ptr ptr ptr)