diff --git a/openhtf/core/phase_descriptor.py b/openhtf/core/phase_descriptor.py
index 1c558cc90..ccd4b3612 100644
--- a/openhtf/core/phase_descriptor.py
+++ b/openhtf/core/phase_descriptor.py
@@ -173,7 +173,7 @@ def name(self):
     return self.options.name or self.func.__name__
 
   @property
-  def doc(self):
+  def __doc__(self):
     return self.func.__doc__
 
   def with_known_args(self, **kwargs):