diff --git a/lib/make-hpc-dist/default.nix b/lib/make-hpc-dist/default.nix
index ad5e7d7..b38a2ec 100644
--- a/lib/make-hpc-dist/default.nix
+++ b/lib/make-hpc-dist/default.nix
@@ -90,10 +90,10 @@ let
     module load singularity/3.10.3
 
     temp_dir="$(mktemp -d)"
-    mkdir -p "$TMPDIR/empty"
+    mkdir -p "''${TMPDIR:-/tmp}/empty"
     function __cleanup {
       echo cleaning up
-      rsync -r --delete -- "$TMPDIR/empty/." "$temp_dir/."
+      rsync -r --delete -- "''${TMPDIR:-/tmp}/empty/." "$temp_dir/."
       rmdir "$temp_dir"
       echo done
     }