diff --git a/include/ceres/cost_function_to_functor.h b/include/ceres/cost_function_to_functor.h
index e17bc0e..bba67a4 100644
--- a/include/ceres/cost_function_to_functor.h
+++ b/include/ceres/cost_function_to_functor.h
@@ -107,7 +107,7 @@
   // Takes ownership of cost_function.
   explicit CostFunctionToFunctor(CostFunction* cost_function)
       : cost_functor_(cost_function) {
-    CHECK_NOTNULL(cost_function);
+    CHECK(cost_function != nullptr);
     CHECK(kNumResiduals > 0 || kNumResiduals == DYNAMIC);
 
     // This block breaks the 80 column rule to keep it somewhat readable.
diff --git a/include/ceres/dynamic_cost_function_to_functor.h b/include/ceres/dynamic_cost_function_to_functor.h
index d4fce1c..7ae5291 100644
--- a/include/ceres/dynamic_cost_function_to_functor.h
+++ b/include/ceres/dynamic_cost_function_to_functor.h
@@ -105,7 +105,7 @@
   // Takes ownership of cost_function.
   explicit DynamicCostFunctionToFunctor(CostFunction* cost_function)
       : cost_function_(cost_function) {
-    CHECK_NOTNULL(cost_function);
+    CHECK(cost_function != nullptr);
   }
 
   bool operator()(double const* const* parameters, double* residuals) const {