diff --git a/bitbake/lib/bb/parse/ast.py b/bitbake/lib/bb/parse/ast.py
index 879c9d28f8..c53ab17d68 100644
--- a/bitbake/lib/bb/parse/ast.py
+++ b/bitbake/lib/bb/parse/ast.py
@@ -139,7 +139,7 @@ class DataNode(AstNode):
             data.setVar(key, val, **loginfo)
 
 class MethodNode(AstNode):
-    tr_tbl = string.maketrans('/.+-@%', '______')
+    tr_tbl = string.maketrans('/.+-@%&', '_______')
 
     def __init__(self, filename, lineno, func_name, body):
         AstNode.__init__(self, filename, lineno)