diff --git a/tda/client/base.py b/tda/client/base.py
index 95076fc..01fdb15 100644
--- a/tda/client/base.py
+++ b/tda/client/base.py
@@ -751,6 +751,7 @@ class Frequency(Enum):
             EVERY_TEN_MINUTES = 10
             EVERY_FIFTEEN_MINUTES = 15
             EVERY_THIRTY_MINUTES = 30
+            EVERY_SIXTY_MINUTES = 60
 
             # Other frequencies
             DAILY = 1