diff --git a/.spellcheck-en-custom.txt b/.spellcheck-en-custom.txt
index 64b9268..ae1a77c 100644
--- a/.spellcheck-en-custom.txt
+++ b/.spellcheck-en-custom.txt
@@ -14,7 +14,6 @@ json
 osbuild
 qcow
 UEFI
-datadir
 copr
 SBOM
 SBOMs
@@ -36,3 +35,4 @@ hyperscalers
 weldr
 libc
 url
+dir
diff --git a/README.md b/README.md
index 377e937..563134b 100644
--- a/README.md
+++ b/README.md
@@ -199,7 +199,7 @@ to the installed image but are not used at build time to install third-party
 packages.
 
 To change repositories during image build time the command line options
-`--datadir`, `--extra-repo` and `--force-repo` can be used. The repositories
+`--data-dir`, `--extra-repo` and `--force-repo` can be used. The repositories
 there will only added during build time and will not be available in the
 installed system (use the above blueprint options if that the goal).
 
@@ -207,9 +207,9 @@ Note that both options are targeting advanced users/use-cases and when
 used wrongly can result in failing image builds or non-booting
 systems.
 
-## Using the datadir switch
+## Using the data-dir switch
 
-When using the `--datadir` flag `image-builder` will look into
+When using the `--data-dir` flag `image-builder` will look into
 the <datadir>/repositories directory for a file called <distro>.json
 that contains the repositories for the <distro>.
 
@@ -246,9 +246,9 @@ A: The osbuild binary is used to actually build the images but beyond that
 
 Q: Can I have custom repository files?
 A: Sure! The repositories are encoded in json in "<distro>-<vesion>.json",
-   files, e.g. "fedora-41.json". See these [examples](https://github.com/osbuild/images/tree/main/data/repositories). Use the "--datadir" switch and
+   files, e.g. "fedora-41.json". See these [examples](https://github.com/osbuild/images/tree/main/data/repositories). Use the "--data-dir" switch and
    place them under "repositories/name-version.json", e.g. for:
-   "--datadir ~/my-project --distro foo-1" a json file must be put under
+   "--data-dir ~/my-project --distro foo-1" a json file must be put under
    "~/my-project/repositories/foo-1.json.
 
 Q: What is the relation to [bootc-image-builder](https://github.com/osbuild/bootc-image-builder)?
diff --git a/cmd/image-builder/main.go b/cmd/image-builder/main.go
index 00c84b3..c53f420 100644
--- a/cmd/image-builder/main.go
+++ b/cmd/image-builder/main.go
@@ -41,7 +41,7 @@ func cmdListImages(cmd *cobra.Command, args []string) error {
 	if err != nil {
 		return err
 	}
-	dataDir, err := cmd.Flags().GetString("datadir")
+	dataDir, err := cmd.Flags().GetString("data-dir")
 	if err != nil {
 		return err
 	}
@@ -79,7 +79,7 @@ func ostreeImageOptions(cmd *cobra.Command) (*ostree.ImageOptions, error) {
 }
 
 func cmdManifestWrapper(pbar progress.ProgressBar, cmd *cobra.Command, args []string, w io.Writer, archChecker func(string) error) (*imagefilter.Result, error) {
-	dataDir, err := cmd.Flags().GetString("datadir")
+	dataDir, err := cmd.Flags().GetString("data-dir")
 	if err != nil {
 		return nil, err
 	}
@@ -284,7 +284,7 @@ func cmdBuild(cmd *cobra.Command, args []string) error {
 
 func cmdDescribeImg(cmd *cobra.Command, args []string) error {
 	// XXX: boilderplate identical to cmdManifest() above
-	dataDir, err := cmd.Flags().GetString("datadir")
+	dataDir, err := cmd.Flags().GetString("data-dir")
 	if err != nil {
 		return err
 	}
@@ -327,7 +327,7 @@ Image-builder builds operating system images for a range of predefined
 operating systems like Fedora, CentOS and RHEL with easy customizations support.`,
 		SilenceErrors: true,
 	}
-	rootCmd.PersistentFlags().String("datadir", "", `Override the default data directory for e.g. custom repositories/*.json data`)
+	rootCmd.PersistentFlags().String("data-dir", "", `Override the default data directory for e.g. custom repositories/*.json data`)
 	rootCmd.PersistentFlags().StringArray("extra-repo", nil, `Add an extra repository during build (will *not* be gpg checked and not be part of the final image)`)
 	rootCmd.PersistentFlags().StringArray("force-repo", nil, `Override the base repositories during build (these will not be part of the final image)`)
 	rootCmd.PersistentFlags().String("output-dir", "", `Put output into the specified directory`)