diff --git a/block/qcow.c b/block/qcow.c
index 7540f43..fb738fc 100644
--- a/block/qcow.c
+++ b/block/qcow.c
@@ -104,6 +104,7 @@
     unsigned int len, i, shift;
     int ret;
     QCowHeader header;
+    Error *local_err = NULL;
 
     ret = bdrv_pread(bs->file, 0, &header, sizeof(header));
     if (ret < 0) {
@@ -252,7 +253,12 @@
     error_setg(&s->migration_blocker, "The qcow format used by node '%s' "
                "does not support live migration",
                bdrv_get_device_or_node_name(bs));
-    migrate_add_blocker(s->migration_blocker);
+    ret = migrate_add_blocker(s->migration_blocker, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        error_free(s->migration_blocker);
+        goto fail;
+    }
 
     qemu_co_mutex_init(&s->lock);
     return 0;
diff --git a/block/vdi.c b/block/vdi.c
index 96b78d5..0aeb940 100644
--- a/block/vdi.c
+++ b/block/vdi.c
@@ -361,6 +361,7 @@
     VdiHeader header;
     size_t bmap_size;
     int ret;
+    Error *local_err = NULL;
 
     logout("\n");
 
@@ -471,7 +472,12 @@
     error_setg(&s->migration_blocker, "The vdi format used by node '%s' "
                "does not support live migration",
                bdrv_get_device_or_node_name(bs));
-    migrate_add_blocker(s->migration_blocker);
+    ret = migrate_add_blocker(s->migration_blocker, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        error_free(s->migration_blocker);
+        goto fail_free_bmap;
+    }
 
     qemu_co_mutex_init(&s->write_lock);
 
diff --git a/block/vhdx.c b/block/vhdx.c
index 0ba2f0a..68db9e0 100644
--- a/block/vhdx.c
+++ b/block/vhdx.c
@@ -991,6 +991,17 @@
         }
     }
 
+    /* Disable migration when VHDX images are used */
+    error_setg(&s->migration_blocker, "The vhdx format used by node '%s' "
+               "does not support live migration",
+               bdrv_get_device_or_node_name(bs));
+    ret = migrate_add_blocker(s->migration_blocker, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        error_free(s->migration_blocker);
+        goto fail;
+    }
+
     if (flags & BDRV_O_RDWR) {
         ret = vhdx_update_headers(bs, s, false, NULL);
         if (ret < 0) {
@@ -1000,12 +1011,6 @@
 
     /* TODO: differencing files */
 
-    /* Disable migration when VHDX images are used */
-    error_setg(&s->migration_blocker, "The vhdx format used by node '%s' "
-               "does not support live migration",
-               bdrv_get_device_or_node_name(bs));
-    migrate_add_blocker(s->migration_blocker);
-
     return 0;
 fail:
     vhdx_close(bs);
diff --git a/block/vmdk.c b/block/vmdk.c
index a11c27a..7750212 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -941,6 +941,7 @@
     int ret;
     BDRVVmdkState *s = bs->opaque;
     uint32_t magic;
+    Error *local_err = NULL;
 
     buf = vmdk_read_desc(bs->file, 0, errp);
     if (!buf) {
@@ -976,7 +977,13 @@
     error_setg(&s->migration_blocker, "The vmdk format used by node '%s' "
                "does not support live migration",
                bdrv_get_device_or_node_name(bs));
-    migrate_add_blocker(s->migration_blocker);
+    ret = migrate_add_blocker(s->migration_blocker, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        error_free(s->migration_blocker);
+        goto fail;
+    }
+
     g_free(buf);
     return 0;
 
diff --git a/block/vpc.c b/block/vpc.c
index 8d5886f..ed6353d 100644
--- a/block/vpc.c
+++ b/block/vpc.c
@@ -422,13 +422,18 @@
 #endif
     }
 
-    qemu_co_mutex_init(&s->lock);
-
     /* Disable migration when VHD images are used */
     error_setg(&s->migration_blocker, "The vpc format used by node '%s' "
                "does not support live migration",
                bdrv_get_device_or_node_name(bs));
-    migrate_add_blocker(s->migration_blocker);
+    ret = migrate_add_blocker(s->migration_blocker, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        error_free(s->migration_blocker);
+        goto fail;
+    }
+
+    qemu_co_mutex_init(&s->lock);
 
     return 0;
 
diff --git a/block/vvfat.c b/block/vvfat.c
index 7b706dc..c6bf67e 100644
--- a/block/vvfat.c
+++ b/block/vvfat.c
@@ -1185,21 +1185,26 @@
 
     s->sector_count = s->faked_sectors + s->sectors_per_cluster*s->cluster_count;
 
-    if (s->first_sectors_number == 0x40) {
-        init_mbr(s, cyls, heads, secs);
-    }
-
-    qemu_co_mutex_init(&s->lock);
-
     /* Disable migration when vvfat is used rw */
     if (s->qcow) {
         error_setg(&s->migration_blocker,
                    "The vvfat (rw) format used by node '%s' "
                    "does not support live migration",
                    bdrv_get_device_or_node_name(bs));
-        migrate_add_blocker(s->migration_blocker);
+        ret = migrate_add_blocker(s->migration_blocker, &local_err);
+        if (local_err) {
+            error_propagate(errp, local_err);
+            error_free(s->migration_blocker);
+            goto fail;
+        }
     }
 
+    if (s->first_sectors_number == 0x40) {
+        init_mbr(s, cyls, heads, secs);
+    }
+
+    qemu_co_mutex_init(&s->lock);
+
     ret = 0;
 fail:
     qemu_opts_del(opts);