diff --git a/gtsam/nonlinear/CMakeLists.txt b/gtsam/nonlinear/CMakeLists.txt
index 5bb2bd7d2..ad4824817 100644
--- a/gtsam/nonlinear/CMakeLists.txt
+++ b/gtsam/nonlinear/CMakeLists.txt
@@ -2,5 +2,8 @@
 file(GLOB nonlinear_headers "*.h")
 install(FILES ${nonlinear_headers} DESTINATION include/gtsam/nonlinear)
 
+file(GLOB nonlinear_headers_internal "internal/*.h")
+install(FILES ${nonlinear_headers_internal} DESTINATION include/gtsam/nonlinear/internal)
+
 # Build tests
 add_subdirectory(tests)