diff --git a/lib/asciidoctor/chat-block-processor/extension.rb b/lib/asciidoctor/chat-block-processor/extension.rb
index ea5d930..52ec823 100644
--- a/lib/asciidoctor/chat-block-processor/extension.rb
+++ b/lib/asciidoctor/chat-block-processor/extension.rb
@@ -24,7 +24,7 @@ class ChatBlock < Asciidoctor::Extensions::BlockProcessor
 
     attrs['avatarsdir'] ||= File.expand_path('./avatars', attrs['iconsdir'])
 
-    avatar_sticker = "#{attrs['avatar'].to_snake}/#{attrs['state'].to_snake}.#{attrs['avatarstype']}"
+    avatar_sticker = "#{attrs['avatar'].to_kebab}/#{attrs['state'].to_kebab}.#{attrs['avatarstype']}"
     avatar_img_attrs = {
       'target' => parent.image_uri(avatar_sticker, 'avatarsdir'),
       'alt' => attrs['name']
diff --git a/lib/asciidoctor/helpers.rb b/lib/asciidoctor/helpers.rb
index e2e7351..2158b38 100644
--- a/lib/asciidoctor/helpers.rb
+++ b/lib/asciidoctor/helpers.rb
@@ -1,10 +1,11 @@
 # frozen_string_literal: true
 
-# Code copied from https://gist.github.com/komasaru/b3f22d5bcb8555deea1707b84d294045.
 class String
-  def to_snake
-    self.gsub(/([A-Z]+)([A-Z][a-z])/, '\1_\2')
-        .gsub(/([a-z\d])([A-Z])/, '\1_\2')
+  def to_kebab
+    self.gsub(/\s+/, '-')           # Replace all spaces with dashes.
+        .gsub(/[^a-zA-Z0-9-]/, '')  # Remove all non-alphanumerical (and dashes) characters.
+        .gsub(/-+/, '-')            # Reduce all dashes into only one.
+        .gsub(/^-|-+$/, '')         # Remove all leading and trailing dashes.
         .downcase
   end
 end