diff --git a/src/slic3r/GUI/GUI_ObjectManipulation.cpp b/src/slic3r/GUI/GUI_ObjectManipulation.cpp
index ee35af6428..5993eb1e11 100644
--- a/src/slic3r/GUI/GUI_ObjectManipulation.cpp
+++ b/src/slic3r/GUI/GUI_ObjectManipulation.cpp
@@ -87,7 +87,7 @@ ObjectManipulation::ObjectManipulation(wxWindow* parent):
         if (option_name == "Rotation")
             def.min = -360;
         else
-            def.min == -1000;
+            def.min = -1000;
 
         const std::string lower_name = boost::algorithm::to_lower_copy(option_name);