diff --git a/mk2rbc/mk2rbc.go b/mk2rbc/mk2rbc.go
index 8f4fea4..d4da4f5 100644
--- a/mk2rbc/mk2rbc.go
+++ b/mk2rbc/mk2rbc.go
@@ -531,7 +531,7 @@
 
 func (ctx *parseContext) handleAssignment(a *mkparser.Assignment) []starlarkNode {
 	// Handle only simple variables
-	if !a.Name.Const() {
+	if !a.Name.Const() || a.Target != nil {
 		return []starlarkNode{ctx.newBadNode(a, "Only simple variables are handled")}
 	}
 	name := a.Name.Strings[0]