diff --git a/regex/doc.go b/regex/doc.go
index c77faf6..b9a59cf 100644
--- a/regex/doc.go
+++ b/regex/doc.go
@@ -153,8 +153,9 @@ returns the 0-group.
 The following features from [regexp] are (currently) NOT supported:
  1. Named capturing groups
  2. Non-greedy operators
- 3. Embedded flags (flags are instead passed as arguments to [Compile])
- 4. Literal text with \Q ... \E
+ 3. Negated POSIX classes
+ 4. Embedded flags (flags are instead passed as arguments to [Compile])
+ 5. Literal text with \Q ... \E
 
 The following features are not available in [regexp], but are supported in my engine:
  1. Lookarounds