diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 5d6de5a..1b27a3c 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -107,17 +107,18 @@ jobs:
           # --max-layers 128: Desktop-Images brauchen mehr als Default (64)
           # --prune /sysroot/: entfernt OSTree-Metadaten (optional seit bootc 1.1.3)
           # --label ostree.*: entfernt gueltigkeitsfaehige ostree-Labels
-          CHUNKAH_DIR=$(mktemp -d)
-          curl -sL https://github.com/coreos/chunkah/releases/download/v0.5.0/Containerfile.splitter -o "$CHUNKAH_DIR/Containerfile"
+          CHUNKAH_CF=$(mktemp)
+          curl -sL https://github.com/coreos/chunkah/releases/download/v0.5.0/Containerfile.splitter -o "$CHUNKAH_CF"
 
           buildah build --skip-unused-stages=false \
+            -f "$CHUNKAH_CF" \
             --from "$IMG" \
             --build-arg CHUNKAH_CONFIG_STR="$CONFIG" \
             --build-arg "CHUNKAH_ARGS=--prune /sysroot/ --max-layers 128 --compressed --label ostree.commit- --label ostree.final-diffid-" \
             -t "$CHUNKED_IMG" \
-            "$CHUNKAH_DIR"
+            .
 
-          rm -rf "$CHUNKAH_DIR"
+          rm -f "$CHUNKAH_CF" out.ociarchive
 
           # Platz freigeben: Original und Zwischenprodukt entfernen
           buildah rmi "$IMG"