diff --git a/README.md b/README.md
index 68c3fb2..b405b3b 100644
--- a/README.md
+++ b/README.md
@@ -100,12 +100,11 @@ git clone https://github.com/xcp-ng-rpms/xapi.git
 # ... Here add your patches ...
 
 # Build.
-xcp-ng-dev container build -b 8.2 --rm xapi/
+xcp-ng-dev container build --rm xapi/ 8.2
 ```
 
 **Important switches**
 
-* `-b` / `--branch` allows to select which version of XCP-ng to work on (defaults to the latest known version if not specified).
 * `--no-exit` drops you to a shell after the build, instead of closing the container. Useful if the build fails and you need to debug.
 * `--rm` destroys the container on exit. Helps preventing containers from using too much space on disk. You can still reclaim space afterwards by running `docker container prune` and `docker image prune`
 * `-v` / `--volume` (see *Mounting repos from outside the container* below)
@@ -120,7 +119,7 @@ fully automated.
    `%autopatch` in the `%prep` block; add `BuildRequires: quilt`
 2. let quilt apply them in a 8.3 buildenv (`quilt` in 8.3 is only in EPEL) and get you a shell:
 ```sh
-xcp-ng-dev container build --rm -b 8.3 --rpmbuild-stage=p -n --enablerepo=epel .
+xcp-ng-dev container build --rm --rpmbuild-stage=p -n --enablerepo=epel 8.3
 ```
 3. ask `quilt` to refresh all your patches (alternatively just the one you want)
 ```sh
@@ -170,5 +169,5 @@ example, if I clone some repos into a directory on my host, say `/work/code/`,
 then I can mount it inside the container as follows:
 
 ```sh
-xcp-ng-dev container shell -b 8.2 -v /work/code:/mnt/repos
+xcp-ng-dev container shell -v /work/code:/mnt/repos 8.2
 ```
diff --git a/src/xcp_ng_dev/cli.py b/src/xcp_ng_dev/cli.py
index 6b37b07..2b60dc4 100755
--- a/src/xcp_ng_dev/cli.py
+++ b/src/xcp_ng_dev/cli.py
@@ -100,7 +100,7 @@ def buildparser():
              "Built RPMs and SRPMs will be in RPMS/ and SRPMS/ subdirectories. "
              "Any preexisting BUILD, BUILDROOT, RPMS or SRPMS directories will be removed first.")
     parser_build.add_argument(
-        'build_local', nargs='?', default='.',
+        'source_dir', nargs='?', default='.',
         help="Root path where SPECS/ and SOURCES are available. "
              "The default is the working directory")
     parser_build.add_argument(
@@ -160,7 +160,7 @@ def container(args):
     if hasattr(args, 'command') and args.command != []:
         docker_args += ["-e", "COMMAND=%s" % ' '.join(args.command)]
     if build:
-        build_dir = os.path.abspath(args.build_local)
+        build_dir = os.path.abspath(args.source_dir)
         docker_args += ["-v", f"{build_dir}:/home/builder/rpmbuild"]
         docker_args += ["-e", "BUILD_LOCAL=1"]
         print(f"Building directory {build_dir}")