diff --git a/wpimath/src/main/native/include/frc/filter/LinearFilter.h b/wpimath/src/main/native/include/frc/filter/LinearFilter.h
index 266d149b9a..e5b6f1db3e 100644
--- a/wpimath/src/main/native/include/frc/filter/LinearFilter.h
+++ b/wpimath/src/main/native/include/frc/filter/LinearFilter.h
@@ -286,7 +286,7 @@ class LinearFilter {
    *
    * @param n Argument of which to take factorial.
    */
-  static int Factorial(int n) {
+  static constexpr int Factorial(int n) {
     if (n < 2) {
       return 1;
     } else {