diff --git a/builder/qemu/builder.go b/builder/qemu/builder.go
index 4ac90dde3..7a293312c 100644
--- a/builder/qemu/builder.go
+++ b/builder/qemu/builder.go
@@ -174,7 +174,9 @@ type Config struct {
 	// and format is qcow2, set this option to true to create a new QCOW2
 	// file that uses the file located at iso_url as a backing file. The new file
 	// will only contain blocks that have changed compared to the backing file, so
-	// enabling this option can significantly reduce disk usage.
+	// enabling this option can significantly reduce disk usage. If true, Packer
+	// will force the `skip_compaction` also to be true as well to skip disk
+	// conversion which would render the backing file feature useless.
 	UseBackingFile bool `mapstructure:"use_backing_file" required:"false"`
 	// The type of machine emulation to use. Run your qemu binary with the
 	// flags `-machine help` to list available types for your system. This
@@ -505,9 +507,12 @@ func (b *Builder) Prepare(raws ...interface{}) ([]string, []string, error) {
 		b.config.DiskCompression = false
 	}
 
-	if b.config.UseBackingFile && !(b.config.DiskImage && b.config.Format == "qcow2") {
-		errs = packer.MultiErrorAppend(
-			errs, errors.New("use_backing_file can only be enabled for QCOW2 images and when disk_image is true"))
+	if b.config.UseBackingFile {
+		b.config.SkipCompaction = true
+		if !(b.config.DiskImage && b.config.Format == "qcow2") {
+			errs = packer.MultiErrorAppend(
+				errs, errors.New("use_backing_file can only be enabled for QCOW2 images and when disk_image is true"))
+		}
 	}
 
 	if b.config.DiskImage && len(b.config.AdditionalDiskSize) > 0 {
diff --git a/website/pages/partials/builder/qemu/Config-not-required.mdx b/website/pages/partials/builder/qemu/Config-not-required.mdx
index 0e1eee693..802b4e0c8 100644
--- a/website/pages/partials/builder/qemu/Config-not-required.mdx
+++ b/website/pages/partials/builder/qemu/Config-not-required.mdx
@@ -96,7 +96,9 @@
   and format is qcow2, set this option to true to create a new QCOW2
   file that uses the file located at iso_url as a backing file. The new file
   will only contain blocks that have changed compared to the backing file, so
-  enabling this option can significantly reduce disk usage.
+  enabling this option can significantly reduce disk usage. If true, Packer
+  will force the `skip_compaction` also to be true as well to skip disk
+  conversion which would render the backing file feature useless.
 
 - `machine_type` (string) - The type of machine emulation to use. Run your qemu binary with the
   flags `-machine help` to list available types for your system. This