diff --git a/wpimath/src/main/native/include/frc/filter/LinearFilter.h b/wpimath/src/main/native/include/frc/filter/LinearFilter.h
index 52eec9de2b2..24a7283cc3f 100644
--- a/wpimath/src/main/native/include/frc/filter/LinearFilter.h
+++ b/wpimath/src/main/native/include/frc/filter/LinearFilter.h
@@ -187,7 +187,7 @@ class LinearFilter {
    */
   template <int Derivative, int Samples>
   static LinearFilter<T> FiniteDifference(
-      const wpi::array<int, Samples> stencil, units::second_t period) {
+      const wpi::array<int, Samples>& stencil, units::second_t period) {
     // See
     // https://en.wikipedia.org/wiki/Finite_difference_coefficient#Arbitrary_stencil_points
     //