diff --git a/grpoppro b/grpoppro
index d4c3afc..9c68039 100755
--- a/grpoppro
+++ b/grpoppro
@@ -49,7 +49,8 @@ function curlRequest {
     -H "$UP_IN_REQ" \
     "$@"
   )"
-  if [[ $? -ne 0 ]]; then
+  exit_code="$?"
+  if [[ "$exit_code" -ne 0 ]]; then
     message "Error: Failed to execute curl request."
     exit 1
   fi