diff --git a/core/utils.py b/core/utils.py
index e817a750..09b9d7f5 100644
--- a/core/utils.py
+++ b/core/utils.py
@@ -6,13 +6,16 @@ from django.utils.translation import ngettext
 def child_age_string(duration):
     """Monkey patch timesince function to day precision only.
     """
+    default_timesine_chunks = timesince.TIMESINCE_CHUNKS
     timesince.TIMESINCE_CHUNKS = (
         (60 * 60 * 24 * 365, 'year'),
         (60 * 60 * 24 * 30, 'month'),
         (60 * 60 * 24 * 7, 'week'),
         (60 * 60 * 24, 'day'),
     )
-    return timesince.timesince(duration)
+    ts = timesince.timesince(duration)
+    timesince.TIMESINCE_CHUNKS = default_timesine_chunks
+    return ts
 
 
 def duration_string(duration, precision='s'):