diff --git a/gtsam/linear/JacobianFactor.cpp b/gtsam/linear/JacobianFactor.cpp
index 579f6cbc2..3cfb5ce7b 100644
--- a/gtsam/linear/JacobianFactor.cpp
+++ b/gtsam/linear/JacobianFactor.cpp
@@ -40,8 +40,8 @@ using namespace std;
 namespace gtsam {
 
 // Typedefs used in constructors below.
-using Dims = std::vector<Eigen::Index>;
-using Pairs = std::vector<std::pair<Eigen::Index, Matrix>>;
+using Dims = std::vector<Key>;
+using Pairs = std::vector<std::pair<Key, Matrix>>;
 
 /* ************************************************************************* */
 JacobianFactor::JacobianFactor() :