diff --git a/geometry/avg_vector.hpp b/geometry/avg_vector.hpp
index 0d1a85b6fd..2a8a02966e 100644
--- a/geometry/avg_vector.hpp
+++ b/geometry/avg_vector.hpp
@@ -96,7 +96,7 @@ namespace math
   public:
     LowPassVector() : m_factor(0.15)
     {
-      m_val.assign(T());
+      m_val.fill(T());
     }
     void SetFactor(T t) { m_factor = t; }