diff --git a/model/cortex-a78x4.sh b/model/cortex-a78x4.sh
index 254408c..5232594 100644
--- a/model/cortex-a78x4.sh
+++ b/model/cortex-a78x4.sh
@@ -12,7 +12,7 @@
 
 source "$ci_root/model/fvp_common.sh"
 
-cat <<EOF >"$model_param_file"
+cat <<EOF >>"${model_param_file}"
 -C bp.terminal_0.start_port=5000
 -C bp.terminal_1.start_port=5001
 -C bp.terminal_2.start_port=5002