diff --git a/src/mathed/InsetMathNest.cpp b/src/mathed/InsetMathNest.cpp
index bc3c2add0e..25f92e9933 100644
--- a/src/mathed/InsetMathNest.cpp
+++ b/src/mathed/InsetMathNest.cpp
@@ -1233,7 +1233,7 @@ void InsetMathNest::doDispatch(Cursor & cur, FuncRequest & cmd)
 		if (cmd.argument() == "^" || cmd.argument() == "_")
 			interpretChar(cur, cmd.argument()[0]);
 		else {
-			MathData ar;
+			MathData ar(cur.buffer());
 			asArray(cmd.argument(), ar);
 			if (cur.selection() && ar.size() == 1
 			    && ar[0]->asNestInset()