diff --git a/experiments/dsv4_h200_vllm_tp_dp_matrix/config.env b/experiments/dsv4_h200_vllm_tp_dp_matrix/config.env
index b9f0398..51401bc 100644
--- a/experiments/dsv4_h200_vllm_tp_dp_matrix/config.env
+++ b/experiments/dsv4_h200_vllm_tp_dp_matrix/config.env
@@ -27,9 +27,9 @@ declare -a PARALLEL_CONFIGS=(
   "8 1"
 )
 
-# Matrix and concurrency rules are defined in matrix.json.
+# Matrix and concurrency rules are defined in matrix.json by default.
 # This file is consumed by generate_scenarios.py.
-MATRIX_FILE="${SCRIPT_DIR:-.}/matrix.json"
+MATRIX_FILE="${MATRIX_FILE:-${SCRIPT_DIR:-.}/matrix.json}"
 MATRIX_MODE="${MATRIX_MODE:-Y}"
 
 # Sampling density for concurrency. 0 means use the default heuristic in