diff --git a/block/copy-on-read.c b/block/copy-on-read.c
index cc0f848b0f..b4d6b7efc3 100644
--- a/block/copy-on-read.c
+++ b/block/copy-on-read.c
@@ -259,7 +259,6 @@ static BlockDriver bdrv_copy_on_read = {
     .bdrv_co_eject                      = cor_co_eject,
     .bdrv_co_lock_medium                = cor_co_lock_medium,
 
-    .has_variable_length                = true,
     .is_filter                          = true,
 };
 
diff --git a/block/filter-compress.c b/block/filter-compress.c
index ac285f4b66..320d9576fa 100644
--- a/block/filter-compress.c
+++ b/block/filter-compress.c
@@ -146,7 +146,6 @@ static BlockDriver bdrv_compress = {
     .bdrv_co_eject                      = compress_co_eject,
     .bdrv_co_lock_medium                = compress_co_lock_medium,
 
-    .has_variable_length                = true,
     .is_filter                          = true,
 };
 
diff --git a/block/preallocate.c b/block/preallocate.c
index 71c3601809..4d82125036 100644
--- a/block/preallocate.c
+++ b/block/preallocate.c
@@ -558,7 +558,6 @@ BlockDriver bdrv_preallocate_filter = {
     .bdrv_set_perm = preallocate_set_perm,
     .bdrv_child_perm = preallocate_child_perm,
 
-    .has_variable_length = true,
     .is_filter = true,
 };
 
diff --git a/block/replication.c b/block/replication.c
index de01f96184..ea4bf1aa80 100644
--- a/block/replication.c
+++ b/block/replication.c
@@ -762,7 +762,6 @@ static BlockDriver bdrv_replication = {
 
     .is_filter                  = true,
 
-    .has_variable_length        = true,
     .strong_runtime_opts        = replication_strong_runtime_opts,
 };