diff --git a/src/mlpack/methods/reinforcement_learning/environment/acrobot.hpp b/src/mlpack/methods/reinforcement_learning/environment/acrobot.hpp
index d00ef43044..638ef6ee3a 100644
--- a/src/mlpack/methods/reinforcement_learning/environment/acrobot.hpp
+++ b/src/mlpack/methods/reinforcement_learning/environment/acrobot.hpp
@@ -351,6 +351,11 @@ class Acrobot
   double doneReward;
 }; // class Acrobot
 
+/**
+ * Add an alias for backward compatibility.
+ */
+typedef Acrobot Acrobat;
+
 } // namespace rl
 } // namespace mlpack