diff --git a/gramps/gen/filters/_searchfilter.py b/gramps/gen/filters/_searchfilter.py
index dfe7a65b6..4b4519e34 100644
--- a/gramps/gen/filters/_searchfilter.py
+++ b/gramps/gen/filters/_searchfilter.py
@@ -31,7 +31,7 @@ class SearchFilter(object):
         self.invert = invert
 
     def match(self, handle, db):
-        return self.invert ^ (self.func(handle).upper().find(self.text) != -1)
+        return self.invert ^ (self.func(handle).upper().find(str(self.text)) != -1)
 
 class ExactSearchFilter(SearchFilter):
     def __init__(self, func, text, invert):