diff --git a/packages/xod-arduino/src/getTokens.js b/packages/xod-arduino/src/getTokens.js
index ff7ce0a1..ac63afe5 100644
--- a/packages/xod-arduino/src/getTokens.js
+++ b/packages/xod-arduino/src/getTokens.js
@@ -2,7 +2,7 @@
 
 const getTokens = () => [
   {
-    regex: /\b((?:input|output)_[A-Z0-9-_]+)\b/gm,
+    regex: /\b((?:input|output)_[A-Za-z0-9-_]+)\b/gm,
     token: 'tag',
   },
   {