diff --git a/src/utils/regex/index.js b/src/utils/regex/index.js
index 1c9be7f..c9844af 100644
--- a/src/utils/regex/index.js
+++ b/src/utils/regex/index.js
@@ -189,7 +189,7 @@ export const endMentionMatch = regexSupplant(/^(?:#{atSigns}|[#{latinAccentChars
 export const validMention = regexSupplant(
   '(#{validMentionPrecedingChars})' + // $1: Preceding character
   '(#{atSigns})' + // $2: At mark
-  '([a-zA-Z0-9_.]{1,20})', // $3: Screen name
+  '([a-zA-Z0-9_\.]{1,20})', // $3: Screen name
   // '(/[a-zA-Z][a-zA-Z0-9_-]{0,24})?', // $4: List (optional)
   { validMentionPrecedingChars, atSigns },
   'g'