diff --git a/src/doc/src/reference/features.md b/src/doc/src/reference/features.md
index 611058e7f..2442233e5 100644
--- a/src/doc/src/reference/features.md
+++ b/src/doc/src/reference/features.md
@@ -87,7 +87,7 @@ optional dependencies. This allows packages to internally enable/disable
 features without requiring a new dependency.
 
 > **Note**: [crates.io] requires feature names to only contain ASCII letters,
-> digits, `_`, or `-`.
+> digits, `_`, `-`, or `+`.
 
 ### Usage in end products