diff --git a/Fire/FireInputController.swift b/Fire/FireInputController.swift
index 993d28d..fd39ba5 100644
--- a/Fire/FireInputController.swift
+++ b/Fire/FireInputController.swift
@@ -186,7 +186,7 @@ class FireInputController: IMKInputController {
         // 获取输入的字符
         let string = event.characters!
 
-        guard let reg = try? NSRegularExpression(pattern: "^[a-z]+$") else {
+        guard let reg = try? NSRegularExpression(pattern: "^[a-zA-Z]+$") else {
             return nil
         }
         let match = reg.firstMatch(