diff --git a/src/handle.cc b/src/handle.cc
index d1e89384321025ed34bf1ab9c201a94749ad3bb8..9deb053a2b09c663b4e893dc385d061a65c4f145 100644
--- a/src/handle.cc
+++ b/src/handle.cc
@@ -62,7 +62,7 @@ namespace hpp {
     bool isHandleOnR3SO3 (const Handle& handle)
     {
       if (handle.joint()->jointModel().shortname() == se3::JointModelFreeFlyer::classname()
-          && handle.joint ()->parentJoint ()) {
+          && !handle.joint ()->parentJoint ()) {
 	return true;
       }
       return false;