diff --git a/math/normalize_vector.h b/math/normalize_vector.h
index ea3a122515c8..357083e541aa 100644
--- a/math/normalize_vector.h
+++ b/math/normalize_vector.h
@@ -40,10 +40,10 @@ void NormalizeVector(
 
     if (ddx_norm) {
       auto dx_norm_transpose = transposeGrad(*dx_norm, x.rows());
-      auto ddx_norm_times_norm = -matGradMultMat(
+      auto minus_ddx_norm_times_norm = matGradMultMat(
           x_norm, x_norm.transpose(), (*dx_norm), dx_norm_transpose);
       auto dnorm_inv = -x.transpose() / (xdotx * norm_x);
-      (*ddx_norm) = ddx_norm_times_norm / norm_x;
+      (*ddx_norm) = -minus_ddx_norm_times_norm / norm_x;
       auto temp = (*dx_norm) * norm_x;
       typename Derived::Index n = x.rows();
       for (int col = 0; col < n; col++) {
diff --git a/systems/rendering/test/pose_aggregator_test.cc b/systems/rendering/test/pose_aggregator_test.cc
index 36a2fbca8e1d..a66448b195ab 100644
--- a/systems/rendering/test/pose_aggregator_test.cc
+++ b/systems/rendering/test/pose_aggregator_test.cc
@@ -208,9 +208,10 @@ TEST_F(PoseAggregatorTest, AddSinglePoseAndVelocityPorts) {
 // Tests that PoseBundle supports Symbolic form.
 GTEST_TEST(PoseBundleTest, Symbolic) {
   PoseBundle<symbolic::Expression> dut{1};
-
+  multibody::SpatialVelocity<symbolic::Expression> msv =
+    dut.get_velocity(0).get_velocity();
   // Just sanity check that some element got zero-initialized.
-  const symbolic::Expression& x = dut.get_velocity(0).get_velocity()[0];
+  const symbolic::Expression& x = msv[0];
   EXPECT_TRUE(x.EqualTo(0.0));
 }