diff --git a/build/amd64-debian-builder.dockerfile b/build/amd64-debian-builder.dockerfile
index 9d451b9..5231e2d 100644
--- a/build/amd64-debian-builder.dockerfile
+++ b/build/amd64-debian-builder.dockerfile
@@ -103,3 +103,6 @@ WORKDIR "$OUTDIR"
 
 ENTRYPOINT ["dumb-init", "--"]
 
+# unused
+ARG QEMU_VERSION_=v3.1.0-2
+
diff --git a/build/amd64-ubuntu-builder.dockerfile b/build/amd64-ubuntu-builder.dockerfile
index bc8d310..d81fe3f 100644
--- a/build/amd64-ubuntu-builder.dockerfile
+++ b/build/amd64-ubuntu-builder.dockerfile
@@ -103,3 +103,6 @@ WORKDIR "$OUTDIR"
 
 ENTRYPOINT ["dumb-init", "--"]
 
+# unused
+ARG QEMU_VERSION_=v3.1.0-2
+