diff --git a/lattice_boltzmann_methods/mpi/d2q9-kernel.cu b/lattice_boltzmann_methods/mpi/d2q9-kernel.cu
index cb285d15ddfb3ee77ab56c8e92f3dfddc7200e0c..53ae9dfcac0d4acca74c367418a80fa532d5ddce 100644
--- a/lattice_boltzmann_methods/mpi/d2q9-kernel.cu
+++ b/lattice_boltzmann_methods/mpi/d2q9-kernel.cu
@@ -1,3 +1,7 @@
+/* 
+** Modified by Youyi Zhang in 2025
+*/
+
 #define NSPEEDS         9
 
 typedef struct