diff --git a/Dockerfile b/Dockerfile
index e4bb069..bc9d430 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -24,7 +24,7 @@ run \
 from debian:bookworm
 entrypoint ["/bin/dkl-local-server"]
 
-env _uncache 1
+env _uncache=1
 run apt-get update \
  && yes |apt-get install -y genisoimage gdisk dosfstools util-linux udev binutils systemd \
  grub2 grub-pc-bin grub-efi-amd64-bin ca-certificates curl openssh-client \