diff --git a/catalyst/finance/risk/period.py b/catalyst/finance/risk/period.py
index 987b8d72..2b072ea9 100644
--- a/catalyst/finance/risk/period.py
+++ b/catalyst/finance/risk/period.py
@@ -29,13 +29,15 @@ from .risk import check_entry
 from empyrical import (
     alpha_beta_aligned,
     annual_volatility,
-    cum_returns,
     downside_risk,
     information_ratio,
-    max_drawdown,
     sharpe_ratio,
     sortino_ratio
 )
+from catalyst.patches.stats import (
+    max_drawdown,
+    cum_returns,
+)
 
 from catalyst.constants import LOG_LEVEL
 
diff --git a/etc/requirements_docs.txt b/etc/requirements_docs.txt
index 362d4725..e89e00e8 100644
--- a/etc/requirements_docs.txt
+++ b/etc/requirements_docs.txt
@@ -1,3 +1,4 @@
 Sphinx>=1.3.2
 numpydoc>=0.5.0
 sphinx-autobuild==0.6.0
+docutils==0.12