diff --git a/css-mixins-1/Overview.bs b/css-mixins-1/Overview.bs
index 5f03832ce5f..f5cb16f7c89 100644
--- a/css-mixins-1/Overview.bs
+++ b/css-mixins-1/Overview.bs
@@ -2344,33 +2344,32 @@ return the concatenation of the following:
2. The result of performing serialize an identifier
on the name of the [=custom function=],
followed by a single LEFT PARENTHESIS (U+0028).
- 4. The result of [=serialize a function parameter=]
+ 3. The result of [=serialize a function parameter=]
on each of the [=custom function's=] [=function parameter|parameters=],
all joined by ", "
(COMMA U+002C, followed by a single SPACE U+0020).
- 5. A single RIGHT PARENTHESIS (U+0029).
- 6. If the [=custom function=] has [=custom function/return type=],
+ 4. A single RIGHT PARENTHESIS (U+0029).
+ 5. If the [=custom function=] has [=custom function/return type=],
and that [=custom function/return type=]
is not the [=universal syntax definition=] ("*"):
* A single SPACE (U+0020),
followed by the string "returns",
followed by a single SPACE (U+0020).
* The result of performing [=serialize a CSS type=]
- on that [=custom function/return type|type=],
- followed by a single SPACE (U+0020).
+ on that [=custom function/return type|type=].
- 7. A single LEFT CURLY BRACKET (U+007B),
- followed by a SPACE (U+0020).
+ 6. A single SPACE (U+0020),
+ followed by a LEFT CURLY BRACKET (U+007B).
- 8. The result of performing [=serialize a CSS rule=]
+ 7. The result of performing [=serialize a CSS rule=]
on each rule in cssRules,
filtering out empty strings,
- all joined by a single SPACE (U+0020).
+ each preceded by a single SPACE (U+0020).
Note: [=Serialize a CSS rule=] can return an empty string
when serializing an empty {{CSSFunctionDeclarations}} rule.
- 9. A single SPACE (U+0020),
+ 8. A single SPACE (U+0020),
followed by a single RIGHT CURLY BRACKET (U+007D).