diff --git a/src/sys/fileinfo.c b/src/sys/fileinfo.c
index 648d3a36..5f8c43c0 100644
--- a/src/sys/fileinfo.c
+++ b/src/sys/fileinfo.c
@@ -896,6 +896,9 @@ static NTSTATUS FspFsvolSetAllocationInformation(PFILE_OBJECT FileObject,
         FspFileNodeSetFileInfo(FileNode, FileObject, &Response->Rsp.SetInformation.FileInfo);
         FileNode->TruncateOnClose = TRUE;
 
+        /* mark the file object as modified */
+        SetFlag(FileObject->Flags, FO_FILE_MODIFIED);
+
         FspFileNodeNotifyChange(FileNode, FILE_NOTIFY_CHANGE_SIZE, FILE_ACTION_MODIFIED);
     }
 
@@ -996,6 +999,9 @@ static NTSTATUS FspFsvolSetEndOfFileInformation(PFILE_OBJECT FileObject,
         FspFileNodeSetFileInfo(FileNode, FileObject, &Response->Rsp.SetInformation.FileInfo);
         FileNode->TruncateOnClose = TRUE;
 
+        /* mark the file object as modified -- FastFat does this only for Allocation though! */
+        SetFlag(FileObject->Flags, FO_FILE_MODIFIED);
+
         FspFileNodeNotifyChange(FileNode, FILE_NOTIFY_CHANGE_SIZE, FILE_ACTION_MODIFIED);
     }
 
diff --git a/src/sys/write.c b/src/sys/write.c
index 550f4a11..24e5e8df 100644
--- a/src/sys/write.c
+++ b/src/sys/write.c
@@ -229,6 +229,9 @@ static NTSTATUS FspFsvolWriteCached(
     if (SynchronousIo)
         FileObject->CurrentByteOffset.QuadPart = WriteEndOffset;
 
+    /* mark the file object as modified (if not paging I/O) */
+    SetFlag(FileObject->Flags, FO_FILE_MODIFIED);
+
     FspFileNodeRelease(FileNode, Main);
 
     return STATUS_SUCCESS;
@@ -432,6 +435,10 @@ NTSTATUS FspFsvolWriteComplete(
                 Response->Rsp.Write.FileInfo.FileSize :
                 WriteOffset.QuadPart + Response->IoStatus.Information;
 
+        /* mark the file object as modified (if not paging I/O) */
+        if (!PagingIo)
+            SetFlag(FileObject->Flags, FO_FILE_MODIFIED);
+
         FspIopResetRequest(Request, 0);
     }
     else
diff --git a/tst/memfs/memfs.cpp b/tst/memfs/memfs.cpp
index bd257acc..0f66c110 100644
--- a/tst/memfs/memfs.cpp
+++ b/tst/memfs/memfs.cpp
@@ -634,7 +634,8 @@ static NTSTATUS Open(FSP_FILE_SYSTEM *FileSystem,
      * To properly implement this we should maintain some state of whether
      * we modified the file or not. Alternatively we could have the driver
      * report to us at Cleanup time whether the file was modified. [The
-     * driver does not currently maintain the FO_FILE_MODIFIED bit however.]
+     * FSD does maintain the FO_FILE_MODIFIED bit, but does not send it
+     * to us.]
      *
      * TBD.
      */