diff --git a/gtsam/base/SymmetricBlockMatrix.h b/gtsam/base/SymmetricBlockMatrix.h
index 378e91144..f6d4fa9c2 100644
--- a/gtsam/base/SymmetricBlockMatrix.h
+++ b/gtsam/base/SymmetricBlockMatrix.h
@@ -256,11 +256,16 @@ namespace gtsam {
       full().triangularView<Eigen::Upper>() = xpr.template triangularView<Eigen::Upper>();
     }
 
-    /// Set the entire active matrix zero.
+    /// Set the entire *active* matrix zero.
     void setZero() {
       full().triangularView<Eigen::Upper>().setZero();
     }
 
+    /// Set entire matrix zero.
+    void setAllZero() {
+      matrix_.setZero();
+    }
+
     /// Negate the entire active matrix.
     void negate();
 
diff --git a/gtsam/linear/HessianFactor.cpp b/gtsam/linear/HessianFactor.cpp
index 701e79f41..f2130f068 100644
--- a/gtsam/linear/HessianFactor.cpp
+++ b/gtsam/linear/HessianFactor.cpp
@@ -245,7 +245,7 @@ HessianFactor::HessianFactor(const GaussianFactorGraph& factors,
 
   // Form A' * A
   gttic(update);
-  info_.setZero();
+  info_.setAllZero();
   for(const auto& factor: factors)
     if (factor)
       factor->updateHessian(keys_, &info_);