diff --git a/include/ceres/solver.h b/include/ceres/solver.h
index 3f9f72f..61b8dd5 100644
--- a/include/ceres/solver.h
+++ b/include/ceres/solver.h
@@ -839,7 +839,7 @@
     int num_linear_solves = -1;
 
     // Time (in seconds) spent evaluating the residual vector.
-    double residual_evaluation_time_in_seconds = 1.0;
+    double residual_evaluation_time_in_seconds = -1.0;
 
     // Number of residual only evaluations.
     int num_residual_evaluations = -1;
diff --git a/internal/ceres/levenberg_marquardt_strategy.h b/internal/ceres/levenberg_marquardt_strategy.h
index 4cadd6d..43b0bfd 100644
--- a/internal/ceres/levenberg_marquardt_strategy.h
+++ b/internal/ceres/levenberg_marquardt_strategy.h
@@ -78,7 +78,7 @@
   // Scaled copy of diagonal_. Stored here as optimization to prevent
   // allocations in every iteration and reuse when a step fails and
   // ComputeStep is called again.
-  Vector lm_diagonal_;  // lm_diagonal_ = diagonal_ / radius_;
+  Vector lm_diagonal_;  // lm_diagonal_ = sqrt(diagonal_ / radius_);
 };
 
 }  // namespace internal