diff --git a/internal/ceres/local_parameterization_test.cc b/internal/ceres/local_parameterization_test.cc
index ec8e660..2847737 100644
--- a/internal/ceres/local_parameterization_test.cc
+++ b/internal/ceres/local_parameterization_test.cc
@@ -271,7 +271,7 @@
   Parameterization parameterization;
   parameterization.Plus(x, delta, x_plus_delta);
   for (int i = 0; i < kGlobalSize; ++i) {
-    EXPECT_NEAR(x_plus_delta[i], x_plus_delta[i], kTolerance);
+    EXPECT_NEAR(x_plus_delta[i], x_plus_delta_ref[i], kTolerance);
   }
 
   const double x_plus_delta_norm = sqrt(