diff --git a/lib-Autodetect-backing-format-for-qemu-img-create-b.patch b/lib-Autodetect-backing-format-for-qemu-img-create-b.patch
new file mode 100644
index 0000000000000000000000000000000000000000..8c901dbcec41736f9fd2a25fe2ccfae00b0742a4
--- /dev/null
+++ b/lib-Autodetect-backing-format-for-qemu-img-create-b.patch
@@ -0,0 +1,45 @@
+From 45de287447bb18d59749fbfc1ec5072413090109 Mon Sep 17 00:00:00 2001
+From: "Richard W.M. Jones" <rjones@redhat.com>
+Date: Tue, 31 Aug 2021 08:27:15 +0100
+Subject: [PATCH] lib: Autodetect backing format for qemu-img create -b
+
+qemu 6.1 has decided to change qemu-img create so that a backing
+format (-F) is required if a backing file (-b) is specified.  Since we
+don't want to change the libguestfs API to force callers to specify
+this because that would be an API break, autodetect it.
+
+This is similar to commit c8c181e8d9 ("launch: libvirt: Autodetect
+backing format for readonly drive overlays").
+
+Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1998820
+---
+ lib/create.c | 9 +++++++++
+ 1 file changed, 9 insertions(+)
+
+diff --git a/lib/create.c b/lib/create.c
+index 44a7df25fc..75a4d3a280 100644
+--- a/lib/create.c
++++ b/lib/create.c
+@@ -255,6 +255,7 @@ disk_create_qcow2 (guestfs_h *g, const char *filename, int64_t size,
+                    const struct guestfs_disk_create_argv *optargs)
+ {
+   const char *backingformat = NULL;
++  CLEANUP_FREE char *backingformat_free = NULL;
+   const char *preallocation = NULL;
+   const char *compat = NULL;
+   int clustersize = -1;
+@@ -270,6 +271,14 @@ disk_create_qcow2 (guestfs_h *g, const char *filename, int64_t size,
+       return -1;
+     }
+   }
++  else if (backingfile) {
++    /* Since qemu 6.1, qemu-img create has requires a backing format (-F)
++     * parameter if backing file (-b) is used (RHBZ#1998820).
++     */
++    backingformat = backingformat_free = guestfs_disk_format (g, backingfile);
++    if (!backingformat)
++      return -1;
++  }
+   if (optargs->bitmask & GUESTFS_DISK_CREATE_PREALLOCATION_BITMASK) {
+     if (STREQ (optargs->preallocation, "off") ||
+         STREQ (optargs->preallocation, "sparse"))
diff --git a/libguestfs.spec b/libguestfs.spec
index f80376726ae9ec80acd5fffc7b435d4ee633ff8a..077a97e165647cafec16c012bd7593b09cfe55f6 100644
--- a/libguestfs.spec
+++ b/libguestfs.spec
@@ -4,7 +4,7 @@
 
 Name:          libguestfs
 Version:       1.40.2
-Release:       19
+Release:       20
 Epoch:         1
 Summary:       A set of tools for accessing and modifying virtual machine (VM) disk images
 License:       LGPLv2+
@@ -20,6 +20,7 @@ Patch0004:     Fix-defaut-function-compare-error.patch
 Patch0005:     Fix-verbose-error.patch
 Patch0006:     0001-tests-Use-explicit-backing-format-for-all-backing-di.patch
 Patch0007:     add-some-package-to-fix-run-error.patch
+Patch0008:     lib-Autodetect-backing-format-for-qemu-img-create-b.patch
 
 BuildRequires: gcc-c++, rpcgen, libtirpc-devel, supermin-devel >= 5.1.18, hivex-devel >= 1.2.7-7, ocaml-hivex-devel, perl(Pod::Simple), perl(Pod::Man)
 BuildRequires: /usr/bin/pod2text, po4a, augeas-devel >= 1.7.0, readline-devel, genisoimage, libxml2-devel, createrepo, glibc-static, libselinux-utils
@@ -378,6 +379,9 @@ chmod 644 %{buildroot}%{_libdir}/perl5/vendor_perl/auto/Sys/Guestfs/Guestfs.so
 %exclude %{_mandir}/man1/virt-tar.1*
 
 %changelog
+* Tue Dec 5 2023 yuxiating <yuxiating@xfusion.com> - 1:1.40.2-20
+- Autodetect backing format for qemu-img create -b
+
 * Mon Aug 14 2023 suwei <suwei@kylinsec.com.cn> -  - 1.40.2-19
 - Add loongarch64 and sw_64 support