diff --git a/ci/pipelines/fx/ensure_env_version.sh b/ci/pipelines/fx/ensure_env_version.sh
index ae2c71a..774c5a4 100755
--- a/ci/pipelines/fx/ensure_env_version.sh
+++ b/ci/pipelines/fx/ensure_env_version.sh
@@ -39,7 +39,7 @@ ensure_env_version() {
     return
   fi
 
-  tmp="$(mktemp)"
+  tmp="$(mktemp 2>/dev/null || mktemp -t envversion)"
   if ! grep -E '^[[:space:]]*[A-Za-z_][A-Za-z0-9_]*=' ./.env.version >"$tmp"; then
     rm -f "$tmp"
     regen_env_version