diff --git a/gtsam/base/LieMatrix.h b/gtsam/base/LieMatrix.h
index 783b8dd47..4c250b3f2 100644
--- a/gtsam/base/LieMatrix.h
+++ b/gtsam/base/LieMatrix.h
@@ -19,6 +19,7 @@
 
 #include <cstdarg>
 
+#warning "LieMatrix.h is deprecated. Please use Eigen::Matrix instead."
 #include <gtsam/base/DerivedValue.h>
 #include <gtsam/base/Lie.h>
 #include <gtsam/base/Matrix.h>
diff --git a/gtsam/base/LieScalar.h b/gtsam/base/LieScalar.h
index ceb0b2f09..c68458364 100644
--- a/gtsam/base/LieScalar.h
+++ b/gtsam/base/LieScalar.h
@@ -17,6 +17,7 @@
 
 #pragma once
 
+#warning "LieScalar.h is deprecated. Please use double/float instead."
 #include <gtsam/dllexport.h>
 #include <gtsam/base/DerivedValue.h>
 #include <gtsam/base/Lie.h>
diff --git a/gtsam/base/LieVector.h b/gtsam/base/LieVector.h
index df39064fe..94ba775cf 100644
--- a/gtsam/base/LieVector.h
+++ b/gtsam/base/LieVector.h
@@ -17,6 +17,7 @@
 
 #pragma once
 
+#warning "LieVector.h is deprecated. Please use Eigen::Vector instead."
 #include <gtsam/base/Lie.h>
 #include <gtsam/base/Vector.h>
 #include <gtsam/base/DerivedValue.h>