diff --git a/tests/mkfs-tests/026-extent-tree-to-bgt/test.sh b/tests/mkfs-tests/026-extent-tree-to-bgt/test.sh
new file mode 100755
index 00000000..f51f0328
--- /dev/null
+++ b/tests/mkfs-tests/026-extent-tree-to-bgt/test.sh
@@ -0,0 +1,25 @@
+#!/bin/bash
+# Test back and forth conversion from extent tree to block-group-tree
+
+source "$TEST_TOP/common"
+
+setup_root_helper
+prepare_test_dev
+
+run_check_mkfs_test_dev -O ^block-group-tree
+run_check_mount_test_dev
+run_check $SUDO_HELPER dd if=/dev/zero of="$TEST_MNT"/file bs=1M count=1
+run_check_umount_test_dev
+
+run_check "$TOP/btrfs" inspect-internal dump-tree "$TEST_DEV"
+run_check "$TOP/btrfs" inspect-internal dump-super "$TEST_DEV"
+run_check "$TOP/btrfstune" --enable-block-group-tree "$TEST_DEV"
+_log "=== AFTER CONVERSION ==="
+run_check "$TOP/btrfs" inspect-internal dump-tree "$TEST_DEV"
+run_check "$TOP/btrfs" inspect-internal dump-super "$TEST_DEV"
+run_check "$TOP/btrfs" check "$TEST_DEV"
+_log "=== BACK CONVERSION ==="
+run_check "$TOP/btrfstune" --disable-block-group-tree "$TEST_DEV"
+run_check "$TOP/btrfs" inspect-internal dump-tree "$TEST_DEV"
+run_check "$TOP/btrfs" inspect-internal dump-super "$TEST_DEV"
+run_check "$TOP/btrfs" check "$TEST_DEV"