diff --git a/asterisk/agi.py b/asterisk/agi.py
index 74d45d7..f19e9a0 100755
--- a/asterisk/agi.py
+++ b/asterisk/agi.py
@@ -129,7 +129,7 @@ class AGI:
           string = str(string)
         if isinstance(string, float):
           string = str(string)
-        return ''.join(['"', string.encode('ascii', 'ignore'), '"'])
+        return ''.join(['"', string.encode('utf8', 'ignore'), '"'])
 
     def _handle_sighup(self, signum, frame):
         """Handle the SIGHUP signal"""