diff --git a/unsupported/Eigen/NonLinearOptimization b/unsupported/Eigen/NonLinearOptimization
index c413af436..f15e09386 100644
--- a/unsupported/Eigen/NonLinearOptimization
+++ b/unsupported/Eigen/NonLinearOptimization
@@ -27,6 +27,7 @@
 
 #include <Eigen/Core>
 #include <Eigen/Jacobi>
+#include <Eigen/QR>
 #include <unsupported/Eigen/NumericalDiff>
 
 namespace Eigen {