diff --git a/src/insets/InsetCollapsible.cpp b/src/insets/InsetCollapsible.cpp
index 58f45b5313..1653386560 100644
--- a/src/insets/InsetCollapsible.cpp
+++ b/src/insets/InsetCollapsible.cpp
@@ -693,7 +693,7 @@ docstring const InsetCollapsible::buttonLabel(BufferView const & bv) const
 	InsetLayout const & il = getLayout();
 	docstring const label = getLabel();
 	if (!il.contentaslabel() || geometry(bv) != ButtonOnly)
-		return indicator + label;
+		return locked + indicator + label;
 	return locked + indicator + getNewLabel(label);
 }