diff --git a/include/ceres/tiny_solver_cost_function_adapter.h b/include/ceres/tiny_solver_cost_function_adapter.h
index 2ba1a2d..d8599e4 100644
--- a/include/ceres/tiny_solver_cost_function_adapter.h
+++ b/include/ceres/tiny_solver_cost_function_adapter.h
@@ -76,7 +76,7 @@
 class TinySolverCostFunctionAdapter {
  public:
   typedef double Scalar;
-  enum {
+  enum ComponentSizeType {
     NUM_PARAMETERS = kNumParameters,
     NUM_RESIDUALS = kNumResiduals
   };