diff --git a/src/serac/physics/state/finite_element_state.hpp b/src/serac/physics/state/finite_element_state.hpp
index ec0551be2a..6f46219e4f 100644
--- a/src/serac/physics/state/finite_element_state.hpp
+++ b/src/serac/physics/state/finite_element_state.hpp
@@ -16,6 +16,7 @@
 #include <functional>
 #include <memory>
 #include <optional>
+#include <type_traits>
 
 #include "mfem.hpp"
 
@@ -73,7 +74,8 @@ decltype(first_argument_helper(&F::operator())) first_argument_helper(F);
  * Extract type of first argument of a free callable
  */
 template <typename T>
-using first_argument = decltype(first_argument_helper(std::declval<T>()));
+using first_argument = typename std::remove_const<
+    typename std::remove_reference<decltype(first_argument_helper(std::declval<T>()))>::type>::type;
 
 /**
  * @brief Evaluate a function of a tensor with an mfem Vector object
diff --git a/src/serac/physics/state/tests/test_finite_element_state.cpp b/src/serac/physics/state/tests/test_finite_element_state.cpp
index 1988febca7..a17238bf36 100644
--- a/src/serac/physics/state/tests/test_finite_element_state.cpp
+++ b/src/serac/physics/state/tests/test_finite_element_state.cpp
@@ -47,7 +47,7 @@ TEST_F(TestFiniteElementState, SetScalarStateFromFieldFunction)
   // Set state with field function.
   // Check that lambda captures work with this.
   double c = 2.0;
-  auto scalar_field = [c](tensor<double, spatial_dim> X) -> double { return c * X[0]; };
+  auto scalar_field = [c](const tensor<double, spatial_dim>& X) -> double { return c * X[0]; };
   scalar_state.setFromFieldFunction(scalar_field);
 
   // Get the nodal positions corresponding to state dofs in a grid function