diff --git a/src/Mod/Path/Path/Base/Gui/Util.py b/src/Mod/Path/Path/Base/Gui/Util.py
index eb567be1e3..0170b33f57 100644
--- a/src/Mod/Path/Path/Base/Gui/Util.py
+++ b/src/Mod/Path/Path/Base/Gui/Util.py
@@ -199,10 +199,10 @@ class QuantitySpinBox(QtCore.QObject):
             self.lastWidgetText = self.widget.text()  # update last widget value
             if expr:
                 self.widget.setReadOnly(True)
-                self.widget.setStyleSheet("color: gray")
+                self.widget.setProperty("exprSet", "true")
             else:
                 self.widget.setReadOnly(False)
-                self.widget.setStyleSheet("color: black")
+                self.widget.setProperty("exprSet", "false")
 
     def updateProperty(self):
         """updateProperty() ... update the bound property with the value from the spin box"""