diff --git a/config/expr_parse_test.go b/config/expr_parse_test.go
index d11519102..da6ab0e43 100644
--- a/config/expr_parse_test.go
+++ b/config/expr_parse_test.go
@@ -17,6 +17,12 @@ func TestExprParse(t *testing.T) {
 			true,
 		},
 
+		{
+			`"foo"`,
+			&LiteralInterpolation{Literal: "foo"},
+			false,
+		},
+
 		{
 			"var.foo",
 			&VariableInterpolation{