diff --git a/gtsam/base/ProductLieGroup.h b/gtsam/base/ProductLieGroup.h
index beb376c19..085da712a 100644
--- a/gtsam/base/ProductLieGroup.h
+++ b/gtsam/base/ProductLieGroup.h
@@ -32,8 +32,8 @@ class ProductLieGroup: public std::pair<G, H> {
   typedef std::pair<G, H> Base;
 
 protected:
-  enum {dimension1 = traits<G>::dimension};
-  enum {dimension2 = traits<H>::dimension};
+  constexpr static const size_t dimension1 = traits<G>::dimension;
+  constexpr static const size_t dimension2 = traits<H>::dimension;
 
 public:
   /// Default constructor yields identity
diff --git a/gtsam/geometry/BearingRange.h b/gtsam/geometry/BearingRange.h
index 19194bb7a..9b8fe1f87 100644
--- a/gtsam/geometry/BearingRange.h
+++ b/gtsam/geometry/BearingRange.h
@@ -55,9 +55,9 @@ private:
   R range_;
 
 public:
-  enum { dimB = traits<B>::dimension };
-  enum { dimR = traits<R>::dimension };
-  enum { dimension = dimB + dimR };
+  constexpr static const size_t dimB = traits<B>::dimension;
+  constexpr static const size_t dimR = traits<R>::dimension;
+  constexpr static const size_t dimension = dimB + dimR;
 
   /// @name Standard Constructors
   /// @{