diff --git a/uv/private/pip_compile_test.sh b/uv/private/pip_compile_test.sh
index e63d6ae..13c4c31 100644
--- a/uv/private/pip_compile_test.sh
+++ b/uv/private/pip_compile_test.sh
@@ -8,17 +8,19 @@ REQUIREMENTS_TXT="{{requirements_txt}}"
 COMPILE_COMMAND="{{compile_command}}"
 
 # make a writable copy of incoming requirements
-cp "$REQUIREMENTS_TXT" __updated__
+updated_file=$(mktemp)
+trap 'rm -f "$updated_file"' EXIT
+cp "$REQUIREMENTS_TXT" "$updated_file"
 
 {{uv}} pip compile \
     --quiet \
     --no-cache \
     {{args}} \
-    --output-file="__updated__" \
+    --output-file="$updated_file" \
     "$REQUIREMENTS_IN"
 
 # check files match
-DIFF="$(diff "$REQUIREMENTS_TXT" "__updated__" || true)"
+DIFF="$(diff "$REQUIREMENTS_TXT" "$updated_file" || true)"
 if [ "$DIFF" != "" ]
 then
   echo >&2 "FAIL: $REQUIREMENTS_TXT is out-of-date. Run '$COMPILE_COMMAND' to update."