diff --git a/google/auth/_helpers.py b/google/auth/_helpers.py
index ecb88ff..21c987a 100644
--- a/google/auth/_helpers.py
+++ b/google/auth/_helpers.py
@@ -22,7 +22,7 @@
 from six.moves import urllib
 
 
-CLOCK_SKEW_SECS = 300  # 5 minutes in seconds
+CLOCK_SKEW_SECS = 10  # 10 seconds
 CLOCK_SKEW = datetime.timedelta(seconds=CLOCK_SKEW_SECS)