diff --git a/algorithms/math/matrix-exponentiation.cpp b/algorithms/math/matrix-exponentiation.cpp
index 52ff9b30..9b63dc4d 100644
--- a/algorithms/math/matrix-exponentiation.cpp
+++ b/algorithms/math/matrix-exponentiation.cpp
@@ -1,4 +1,4 @@
-ll MOD = 1'000'000'007;
+const ll MOD = 1'000'000'007;
 
 template <typename T>
 vector<vector<T>> prod(vector<vector<T>> &a,