diff --git a/src/Base/CoordinateSystem.cpp b/src/Base/CoordinateSystem.cpp
index f1f6c35f7f..bd61263cd1 100644
--- a/src/Base/CoordinateSystem.cpp
+++ b/src/Base/CoordinateSystem.cpp
@@ -88,7 +88,7 @@ void CoordinateSystem::setXDirection(const Vector3d& dir)
 
 void CoordinateSystem::setYDirection(const Vector3d& dir)
 {
-    Vector3d xd = dir & axis.getDirection();
+    Vector3d xd = dir % axis.getDirection();
     if (xd.Sqr() < Base::Vector3d::epsilon())
         throw Base::ValueError("Direction is parallel to Z direction");
     xdir = xd;