diff --git a/gtsam/slam/KarcherMeanFactor-inl.h b/gtsam/slam/KarcherMeanFactor-inl.h
index 8ff61d796..076b0ff0c 100644
--- a/gtsam/slam/KarcherMeanFactor-inl.h
+++ b/gtsam/slam/KarcherMeanFactor-inl.h
@@ -41,8 +41,14 @@ T FindKarcherMeanImpl(const vector<T, ALLOC>& rotations) {
   return result.at<T>(kKey);
 }
 
-template <class T, class ALLOC>
-T FindKarcherMean(const vector<T, ALLOC>& rotations) {
+template <class T,
+        typename = typename std::enable_if< std::is_same<gtsam::Rot3, T>::value >::type >
+T FindKarcherMean(const std::vector<T>& rotations) {
+  return FindKarcherMeanImpl(rotations);
+}
+
+template <class T>
+T FindKarcherMean(const std::vector<T, Eigen::aligned_allocator<T>>& rotations) {
   return FindKarcherMeanImpl(rotations);
 }
 
diff --git a/gtsam/slam/KarcherMeanFactor.h b/gtsam/slam/KarcherMeanFactor.h
index f62cb8904..54b3930d4 100644
--- a/gtsam/slam/KarcherMeanFactor.h
+++ b/gtsam/slam/KarcherMeanFactor.h
@@ -29,8 +29,8 @@ namespace gtsam {
  * the given rotations, by constructing a factor graph out of simple
  * PriorFactors.
  */
-template <class T, class ALLOC = Eigen::aligned_allocator<T>>
-T FindKarcherMean(const std::vector<T, ALLOC>& rotations);
+template <class T>
+T FindKarcherMean(const std::vector<T, Eigen::aligned_allocator<T>>& rotations);
 
 template <class T>
 T FindKarcherMean(std::initializer_list<T>&& rotations);
diff --git a/gtsam/slam/tests/testKarcherMeanFactor.cpp b/gtsam/slam/tests/testKarcherMeanFactor.cpp
index 64cdb1682..c129b8fa3 100644
--- a/gtsam/slam/tests/testKarcherMeanFactor.cpp
+++ b/gtsam/slam/tests/testKarcherMeanFactor.cpp
@@ -75,7 +75,7 @@ static const SO4 Q = SO4::Expmap((Vector6() << 1, 2, 3, 4, 5, 6).finished());
 
 /* ************************************************************************* */
 TEST(KarcherMean, FindSO4) {
-  std::vector<SO4> rotations = {Q, Q.inverse()};
+  std::vector<SO4, Eigen::aligned_allocator<SO4>> rotations = {Q, Q.inverse()};
   auto expected = SO4();  //::ChordalMean(rotations);
   auto actual = FindKarcherMean(rotations);
   EXPECT(assert_equal(expected, actual));