diff --git a/src/builtin/list.rs b/src/builtin/list.rs
index fd21cae..b44e055 100644
--- a/src/builtin/list.rs
+++ b/src/builtin/list.rs
@@ -147,13 +147,13 @@ pub(crate) fn register(f: &mut HashMap<String, Builtin>) {
         "join".to_owned(),
         Box::new(|mut args, _| {
             max_args!(args, 3);
-            let (mut list1, sep1, brackets) = match arg!(args, 0, "list") {
+            let (mut list1, sep1, brackets) = match arg!(args, 0, "list1") {
                 Value::List(v, sep, brackets) => (v, sep, brackets),
                 v => (vec![v], ListSeparator::Space, Brackets::None),
             };
-            let list2 = match arg!(args, 1, "list") {
-                Value::List(v, ..) => v,
-                v => vec![v],
+            let (list2, sep2) = match arg!(args, 1, "list2") {
+                Value::List(v, sep, ..) => (v, sep),
+                v => (vec![v], ListSeparator::Space),
             };
             let sep = match arg!(
                 args,
diff --git a/tests/list.rs b/tests/list.rs
index c6f8f25..c138baa 100644
--- a/tests/list.rs
+++ b/tests/list.rs
@@ -163,10 +163,25 @@ test!(
     "a {\n  color: a b c d;\n}\n"
 );
 test!(
-    join_bracketed,
+    join_first_bracketed,
     "a {\n  color: join([a], b);\n}\n",
     "a {\n  color: [a b];\n}\n"
 );
+test!(
+    join_second_bracketed,
+    "a {\n  color: join(a, [b]);\n}\n",
+    "a {\n  color: a b;\n}\n"
+);
+test!(
+    join_space_comma,
+    "a {\n  color: join(a b, (c,));\n}\n",
+    "a {\n  color: a b c;\n}\n"
+);
+test!(
+    join_comma_space,
+    "a {\n  color: join((a, b), (c));\n}\n",
+    "a {\n  color: a, b, c;\n}\n"
+);
 test!(bracketed_ident, "a {\n  color: [a];\n}\n");
 test!(bracketed_space_list, "a {\n  color: [a b];\n}\n");
 test!(bracketed_comma_list, "a {\n  color: [a, b];\n}\n");