diff --git a/tests/url_serialize.rs b/tests/url_serialize.rs
index 5a48e931..ad293d0f 100644
--- a/tests/url_serialize.rs
+++ b/tests/url_serialize.rs
@@ -84,86 +84,65 @@ fn serialize_unit_type() {
     assert_eq!(urlencoded::to_string(()), Ok("".to_owned()));
 }
 
-#[derive(Serialize)]
-struct Wrapper<T> {
-    item: T,
-}
-
-#[derive(Serialize)]
-struct NewStruct {
-    list: Vec<String>,
-}
-
-#[derive(Serialize)]
-struct Struct {
-    list: Vec<Option<String>>,
-}
-
-#[derive(Serialize)]
-struct ListStruct {
-    list: Vec<NewType<usize>>,
-}
-
 #[test]
-fn serialize_newstruct() {
-    let s = NewStruct {
-        list: vec!["hello".into(), "world".into()],
-    };
+fn serialize_list_of_str() {
+    let s = &[("list", vec!["hello", "world"])];
+
     assert_eq!(
-        "list=hello&list=world".to_string(),
-        urlencoded::to_string(s).unwrap()
+        urlencoded::to_string(s),
+        Ok("list=hello&list=world".to_owned())
     );
 }
 
 #[test]
-fn serialize_vec_bool() {
-    let params = Wrapper {
-        item: vec![true, false, false],
+fn serialize_multiple_lists() {
+    #[derive(Serialize)]
+    struct Lists {
+        xs: Vec<bool>,
+        ys: Vec<u32>,
+    }
+
+    let params = Lists {
+        xs: vec![true, false],
+        ys: vec![3, 2, 1],
     };
+
     assert_eq!(
-        urlencoded::to_string(params).unwrap(),
-        "item=true&item=false&item=false".to_owned()
+        urlencoded::to_string(params),
+        Ok("xs=true&xs=false&ys=3&ys=2&ys=1".to_owned())
     );
 }
 
 #[test]
 fn serialize_vec_num() {
-    let params = Wrapper {
-        item: vec![0, 1, 2],
-    };
+    let params = [("item", vec![0, 1, 2])];
     assert_eq!(
-        urlencoded::to_string(params).unwrap(),
-        "item=0&item=1&item=2".to_owned()
+        urlencoded::to_string(params),
+        Ok("item=0&item=1&item=2".to_owned())
     );
 }
 
 #[test]
 fn serialize_vec_str() {
-    let params = Wrapper {
-        item: vec!["hello", "world", "hello"],
-    };
+    let params = &[("item", vec!["hello", "world", "hello"])];
     assert_eq!(
-        urlencoded::to_string(params).unwrap(),
-        "item=hello&item=world&item=hello".to_owned()
+        urlencoded::to_string(params),
+        Ok("item=hello&item=world&item=hello".to_owned())
     );
 }
 
 #[test]
 fn serialize_struct_opt() {
-    let s = Struct {
-        list: vec![Some("hello".into()), Some("world".into())],
-    };
+    let s = &[("list", vec![Some("hello"), Some("world")])];
     assert_eq!(
-        "list=hello&list=world".to_string(),
-        urlencoded::to_string(s).unwrap()
+        urlencoded::to_string(s),
+        Ok("list=hello&list=world".to_string())
     );
 }
 
 #[test]
 fn serialize_struct_newtype() {
-    let s = ListStruct {
-        list: vec![NewType(0), NewType(1)],
-    };
+    let s = &[("list", vec![NewType(0), NewType(1)])];
     assert_eq!(
         "list=0&list=1".to_string(),
         urlencoded::to_string(s).unwrap()
@@ -172,9 +151,7 @@ fn serialize_struct_newtype() {
 
 #[test]
 fn serialize_struct_unit_enum() {
-    let params = Wrapper {
-        item: vec![X::A, X::B, X::C],
-    };
+    let params = &[("item", vec![X::A, X::B, X::C])];
     assert_eq!(
         urlencoded::to_string(params),
         Ok("item=A&item=B&item=C".to_owned())