diff --git a/hive/utils/normalize.py b/hive/utils/normalize.py
index ee7b220167553f5e3d1d786021c0a2c89c96a189..f0a2f61421d6a3c1d09ff0e3dc1e5fe340b2398d 100644
--- a/hive/utils/normalize.py
+++ b/hive/utils/normalize.py
@@ -68,6 +68,7 @@ def to_nai(value):
 
 def escape_characters(text):
     """ Escape special charactes """
+    assert isinstance(text, str), "Expected string got: {}".format(type(text))
     if len(text.strip()) == 0:
         return "'" + text + "'"