diff --git a/src/slic3r/GUI/Selection.cpp b/src/slic3r/GUI/Selection.cpp
index 5b44f4fd58..333c7a9ce7 100644
--- a/src/slic3r/GUI/Selection.cpp
+++ b/src/slic3r/GUI/Selection.cpp
@@ -1047,14 +1047,7 @@ void Selection::rotate(const Vec3d& rotation, TransformationType transformation_
     if (m_mode == Instance) {
         int rot_axis_max = 0;
         rotation.cwiseAbs().maxCoeff(&rot_axis_max);
-        SyncRotationType synch;
-        if (transformation_type.world() && rot_axis_max == 2)
-            synch = SyncRotationType::NONE;
-        else if (transformation_type.instance())
-            synch = SyncRotationType::FULL;
-        else
-            synch = SyncRotationType::GENERAL;
-        synchronize_unselected_instances(synch);
+        synchronize_unselected_instances((transformation_type.world() && rot_axis_max == 2) ? SyncRotationType::NONE : SyncRotationType::GENERAL);
     }
     else if (m_mode == Volume)
         synchronize_unselected_volumes();
@@ -1483,7 +1476,9 @@ void Selection::scale_and_translate(const Vec3d& scale, const Vec3d& translation
 
 #if !DISABLE_INSTANCES_SYNCH
     if (m_mode == Instance)
-        synchronize_unselected_instances(SyncRotationType::NONE);
+        // even if there is no rotation, we pass SyncRotationType::GENERAL to force 
+        // synchronize_unselected_instances() to apply the scale to the other instances
+        synchronize_unselected_instances(SyncRotationType::GENERAL);
     else if (m_mode == Volume)
         synchronize_unselected_volumes();
 #endif // !DISABLE_INSTANCES_SYNCH
diff --git a/src/slic3r/GUI/Selection.hpp b/src/slic3r/GUI/Selection.hpp
index 29398eabfd..654e3c22dd 100644
--- a/src/slic3r/GUI/Selection.hpp
+++ b/src/slic3r/GUI/Selection.hpp
@@ -497,10 +497,6 @@ public:
         NONE = 0,
         // Synchronize after rotation by an axis not parallel with Z.
         GENERAL = 1,
-#if ENABLE_WORLD_COORDINATE
-        // Fully synchronize rotation.
-        FULL = 2,
-#endif // ENABLE_WORLD_COORDINATE
     };
     void synchronize_unselected_instances(SyncRotationType sync_rotation_type);
     void synchronize_unselected_volumes();