diff --git a/src/calibre/utils/genshi/template/eval.py b/src/calibre/utils/genshi/template/eval.py
index d9bbc846d3..0e9fae6d64 100644
--- a/src/calibre/utils/genshi/template/eval.py
+++ b/src/calibre/utils/genshi/template/eval.py
@@ -177,7 +177,10 @@ class Expression(Code):
         """
         __traceback_hide__ = 'before_and_this'
         _globals = self._globals(data)
-        return eval(self.code, _globals, {'__data__': data})
+        code = self.code
+        if not isinstance(code, unicode):
+            code = code.decode('utf-8', 'replace')
+        return eval(code, _globals, {'__data__': data})
 
 
 class Suite(Code):