diff --git a/src/calibre/library/field_metadata.py b/src/calibre/library/field_metadata.py
index 07c90119bd..243e3646da 100644
--- a/src/calibre/library/field_metadata.py
+++ b/src/calibre/library/field_metadata.py
@@ -195,11 +195,11 @@ class FieldMetadata(dict):
                            'is_category':False}),
             ('ondevice',  {'table':None,
                            'column':None,
-                           'datatype':'bool',
+                           'datatype':'text',
                            'is_multiple':None,
                            'kind':'field',
                            'name':None,
-                           'search_terms':[],
+                           'search_terms':['ondevice'],
                            'is_custom':False,
                            'is_category':False}),
             ('path',      {'table':None,