diff --git a/block/blkdebug.c b/block/blkdebug.c
index 589712475a..762ec2527c 100644
--- a/block/blkdebug.c
+++ b/block/blkdebug.c
@@ -398,10 +398,11 @@ static int blkdebug_open(BlockDriverState *bs, QDict *options, int flags,
         goto out;
     }
 
-    bs->supported_write_flags = BDRV_REQ_FUA &
-        bs->file->bs->supported_write_flags;
-    bs->supported_zero_flags = (BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP) &
-        bs->file->bs->supported_zero_flags;
+    bs->supported_write_flags = BDRV_REQ_WRITE_UNCHANGED |
+        (BDRV_REQ_FUA & bs->file->bs->supported_write_flags);
+    bs->supported_zero_flags = BDRV_REQ_WRITE_UNCHANGED |
+        ((BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP) &
+            bs->file->bs->supported_zero_flags);
     ret = -EINVAL;
 
     /* Set alignment overrides */
diff --git a/block/blkreplay.c b/block/blkreplay.c
index fe5a9b4a98..b016dbeee7 100755
--- a/block/blkreplay.c
+++ b/block/blkreplay.c
@@ -35,6 +35,9 @@ static int blkreplay_open(BlockDriverState *bs, QDict *options, int flags,
         goto fail;
     }
 
+    bs->supported_write_flags = BDRV_REQ_WRITE_UNCHANGED;
+    bs->supported_zero_flags = BDRV_REQ_WRITE_UNCHANGED;
+
     ret = 0;
 fail:
     return ret;
diff --git a/block/blkverify.c b/block/blkverify.c
index 331365be33..1646404b46 100644
--- a/block/blkverify.c
+++ b/block/blkverify.c
@@ -141,6 +141,9 @@ static int blkverify_open(BlockDriverState *bs, QDict *options, int flags,
         goto fail;
     }
 
+    bs->supported_write_flags = BDRV_REQ_WRITE_UNCHANGED;
+    bs->supported_zero_flags = BDRV_REQ_WRITE_UNCHANGED;
+
     ret = 0;
 fail:
     qemu_opts_del(opts);
diff --git a/block/cor.c b/block/cor.c
index a4cb4e2b84..189e5bd13e 100644
--- a/block/cor.c
+++ b/block/cor.c
@@ -33,11 +33,13 @@ static int cor_open(BlockDriverState *bs, QDict *options, int flags,
         return -EINVAL;
     }
 
-    bs->supported_write_flags = BDRV_REQ_FUA &
-                                    bs->file->bs->supported_write_flags;
+    bs->supported_write_flags = BDRV_REQ_WRITE_UNCHANGED |
+                                (BDRV_REQ_FUA &
+                                    bs->file->bs->supported_write_flags);
 
-    bs->supported_zero_flags = (BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP) &
-                                    bs->file->bs->supported_zero_flags;
+    bs->supported_zero_flags = BDRV_REQ_WRITE_UNCHANGED |
+                               ((BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP) &
+                                    bs->file->bs->supported_zero_flags);
 
     return 0;
 }
diff --git a/block/mirror.c b/block/mirror.c
index 820f512c7b..6fdd36d27f 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -1148,6 +1148,8 @@ static void mirror_start_job(const char *job_id, BlockDriverState *bs,
         mirror_top_bs->implicit = true;
     }
     mirror_top_bs->total_sectors = bs->total_sectors;
+    mirror_top_bs->supported_write_flags = BDRV_REQ_WRITE_UNCHANGED;
+    mirror_top_bs->supported_zero_flags = BDRV_REQ_WRITE_UNCHANGED;
     bdrv_set_aio_context(mirror_top_bs, bdrv_get_aio_context(bs));
 
     /* bdrv_append takes ownership of the mirror_top_bs reference, need to keep
diff --git a/block/raw-format.c b/block/raw-format.c
index a378547c99..fe33693a2d 100644
--- a/block/raw-format.c
+++ b/block/raw-format.c
@@ -415,10 +415,11 @@ static int raw_open(BlockDriverState *bs, QDict *options, int flags,
     }
 
     bs->sg = bs->file->bs->sg;
-    bs->supported_write_flags = BDRV_REQ_FUA &
-        bs->file->bs->supported_write_flags;
-    bs->supported_zero_flags = (BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP) &
-        bs->file->bs->supported_zero_flags;
+    bs->supported_write_flags = BDRV_REQ_WRITE_UNCHANGED |
+        (BDRV_REQ_FUA & bs->file->bs->supported_write_flags);
+    bs->supported_zero_flags = BDRV_REQ_WRITE_UNCHANGED |
+        ((BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP) &
+            bs->file->bs->supported_zero_flags);
 
     if (bs->probed && !bdrv_is_read_only(bs)) {
         fprintf(stderr,
diff --git a/block/throttle.c b/block/throttle.c
index 95ed06acd8..e298827f95 100644
--- a/block/throttle.c
+++ b/block/throttle.c
@@ -81,8 +81,10 @@ static int throttle_open(BlockDriverState *bs, QDict *options,
     if (!bs->file) {
         return -EINVAL;
     }
-    bs->supported_write_flags = bs->file->bs->supported_write_flags;
-    bs->supported_zero_flags = bs->file->bs->supported_zero_flags;
+    bs->supported_write_flags = bs->file->bs->supported_write_flags |
+                                BDRV_REQ_WRITE_UNCHANGED;
+    bs->supported_zero_flags = bs->file->bs->supported_zero_flags |
+                               BDRV_REQ_WRITE_UNCHANGED;
 
     return throttle_configure_tgm(bs, tgm, options, errp);
 }
