diff --git a/config/interpolate_walk_test.go b/config/interpolate_walk_test.go
index fc7c8b549..b5c9a3a92 100644
--- a/config/interpolate_walk_test.go
+++ b/config/interpolate_walk_test.go
@@ -18,7 +18,9 @@ func TestInterpolationWalker_detect(t *testing.T) {
 			Input: map[string]interface{}{
 				"foo": "$${var.foo}",
 			},
-			Result: nil,
+			Result: []string{
+				"Literal(TypeString, ${var.foo})",
+			},
 		},
 
 		{
@@ -114,7 +116,7 @@ func TestInterpolationWalker_replace(t *testing.T) {
 				"foo": "$${var.foo}",
 			},
 			Output: map[string]interface{}{
-				"foo": "$${var.foo}",
+				"foo": "bar",
 			},
 			Value: "bar",
 		},