diff --git a/corelib/include/rtabmap/core/Parameters.h b/corelib/include/rtabmap/core/Parameters.h
index 803751e7..aca997f3 100644
--- a/corelib/include/rtabmap/core/Parameters.h
+++ b/corelib/include/rtabmap/core/Parameters.h
@@ -226,7 +226,7 @@ class RTABMAP_EXP Parameters
 	RTABMAP_PARAM(RGBD, AngularUpdate,     float, 0.0, 	"Min angular displacement to update the map. Rehearsal is done prior to this, so weights are still updated.");
 	RTABMAP_PARAM(RGBD, NewMapOdomChangeDistance, float, 0, "A new map is created if a change of odometry translation greater than X m is detected (0 m = disabled).");
 	RTABMAP_PARAM(RGBD, ToroIterations,    int, 100,    "TORO graph optimization iterations");
-	RTABMAP_PARAM(RGBD, OptimizeFromGraphEnd, bool, true,    "Optimize graph from the newest node. If false, the graph is optimized from the oldest node of the current graph (this adds an overhead computation to detect to oldest mode of the current graph, but it can be useful to preserve the map referential from the oldest node).");
+	RTABMAP_PARAM(RGBD, OptimizeFromGraphEnd, bool, true,    "Optimize graph from the newest node. If false, the graph is optimized from the oldest node of the current graph (this adds an overhead computation to detect to oldest mode of the current graph, but it can be useful to preserve the map referential from the oldest node). Warning when set to false: when some nodes are transfered, the first referential of the local may change, resulting in momentary changes in robot/map position (which are annoying in teleoperation).");
 
 	// Local loop closure detection
 	RTABMAP_PARAM(RGBD, LocalLoopDetectionTime,     bool, true, 	"Detection over all locations in STM.");
diff --git a/guilib/src/ui/preferencesDialog.ui b/guilib/src/ui/preferencesDialog.ui
index 0a7d91b4..97d066fd 100644
--- a/guilib/src/ui/preferencesDialog.ui
+++ b/guilib/src/ui/preferencesDialog.ui
@@ -63,9 +63,9 @@
           <property name="geometry">
            <rect>
             <x>0</x>
-            <y>-210</y>
+            <y>-530</y>
             <width>709</width>
-            <height>1089</height>
+            <height>1140</height>
            </rect>
           </property>
           <layout class="QVBoxLayout" name="verticalLayout_16">
@@ -4569,7 +4569,8 @@ If set to false, classic RTAB-Map loop closure detection is done using only imag
                        <item row="1" column="1">
                         <widget class="QLabel" name="label_151">
                          <property name="text">
-                          <string>Optimize graph from the newest node. If false, the graph is optimized from the oldest node of the current graph (this adds an overhead computation to detect to oldest mode of the current graph, but it can be useful to preserve the map referential from the oldest node).</string>
+                          <string>Optimize graph from the newest node. If false, the graph is optimized from the oldest node of the current graph (this adds an overhead computation to detect to oldest mode of the current graph, but it can be useful to preserve the map referential from the oldest node). 
+Warning when set to false: when some nodes are transfered, the first referential of the local may change, resulting in momentary changes in robot/map position (which are annoying in teleoperation).</string>
                          </property>
                          <property name="wordWrap">
                           <bool>true</bool>