diff --git a/hy/compiler.py b/hy/compiler.py
index bd74021..a112d3a 100644
--- a/hy/compiler.py
+++ b/hy/compiler.py
@@ -84,7 +84,7 @@ def ast_str(foobar):
 
     enc = codecs.getencoder('punycode')
     foobar, _ = enc(foobar)
-    return "__hy_%s" % (str(foobar).replace("-", "_"))
+    return "hy_%s" % (str(foobar).replace("-", "_"))
 
 
 def builds(_type):