diff --git a/gtsam/nonlinear/nonlinear.i b/gtsam/nonlinear/nonlinear.i
index 293b666ae..68d30c56c 100644
--- a/gtsam/nonlinear/nonlinear.i
+++ b/gtsam/nonlinear/nonlinear.i
@@ -598,6 +598,9 @@ class ISAM2Params {
   bool enableDetailedResults;
   bool enablePartialRelinearizationCheck;
   bool findUnusedFactorSlots;
+
+  enum Factorization { CHOLESKY, QR };
+  Factorization factorization;
 };
 
 class ISAM2Clique {