diff --git a/vlib/v/gen/c/array.v b/vlib/v/gen/c/array.v
index c3a06d3ec6..d264a4c7c7 100644
--- a/vlib/v/gen/c/array.v
+++ b/vlib/v/gen/c/array.v
@@ -762,6 +762,9 @@ fn (mut g Gen) gen_array_index(node ast.CallExpr) {
 	}
 	g.expr(node.left)
 	g.write(', ')
+	if node.args[0].expr.is_auto_deref_var() {
+		g.write('*')
+	}
 	g.expr(node.args[0].expr)
 	g.write(')')
 }
diff --git a/vlib/v/tests/for_in_mut_array_index_test.v b/vlib/v/tests/for_in_mut_array_index_test.v
new file mode 100644
index 0000000000..f4c628e880
--- /dev/null
+++ b/vlib/v/tests/for_in_mut_array_index_test.v
@@ -0,0 +1,12 @@
+fn test_for_in_mut_array_index() {
+	mut arr := [1, 2, 3, 4, 5]
+	mut rets := []int{}
+
+	for mut val in arr {
+		inx := arr.index(val)
+		println(inx)
+		rets << inx
+	}
+
+	assert rets == [0, 1, 2, 3, 4]
+}