Beginnings of a constant_time module.
diff --git a/docs/hazmat/primitives/index.rst b/docs/hazmat/primitives/index.rst
index 614c414..b115fdb 100644
--- a/docs/hazmat/primitives/index.rst
+++ b/docs/hazmat/primitives/index.rst
@@ -10,4 +10,5 @@
     hmac
     symmetric-encryption
     padding
+    constant-time
     interfaces