diff --git a/gtsam_unstable/nonlinear/Expression-inl.h b/gtsam/nonlinear/Expression-inl.h
similarity index 100%
rename from gtsam_unstable/nonlinear/Expression-inl.h
rename to gtsam/nonlinear/Expression-inl.h
diff --git a/gtsam_unstable/nonlinear/Expression.h b/gtsam/nonlinear/Expression.h
similarity index 99%
rename from gtsam_unstable/nonlinear/Expression.h
rename to gtsam/nonlinear/Expression.h
index 68a79ed6b..85b223440 100644
--- a/gtsam_unstable/nonlinear/Expression.h
+++ b/gtsam/nonlinear/Expression.h
@@ -19,7 +19,7 @@
 
 #pragma once
 
-#include "Expression-inl.h"
+#include <gtsam/nonlinear/Expression-inl.h>
 #include <gtsam/base/FastVector.h>
 #include <gtsam/inference/Symbol.h>
 
diff --git a/gtsam_unstable/nonlinear/tests/testExpression.cpp b/gtsam/nonlinear/tests/testExpression.cpp
similarity index 99%
rename from gtsam_unstable/nonlinear/tests/testExpression.cpp
rename to gtsam/nonlinear/tests/testExpression.cpp
index 6156d103c..dfa60e54e 100644
--- a/gtsam_unstable/nonlinear/tests/testExpression.cpp
+++ b/gtsam/nonlinear/tests/testExpression.cpp
@@ -17,9 +17,9 @@
  * @brief unit tests for Block Automatic Differentiation
  */
 
+#include <gtsam/nonlinear/Expression.h>
 #include <gtsam/geometry/PinholeCamera.h>
 #include <gtsam/geometry/Cal3_S2.h>
-#include <gtsam_unstable/nonlinear/Expression.h>
 #include <gtsam/base/Testable.h>
 #include <gtsam/base/LieScalar.h>