diff --git a/CMakeLists.txt b/CMakeLists.txt
index dd626bde8..f0b127051 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -200,34 +200,39 @@ option(GTSAM_USE_SYSTEM_EIGEN "Find and use system-installed Eigen. If 'off', us
 
 # Switch for using system Eigen or GTSAM-bundled Eigen
 if(GTSAM_USE_SYSTEM_EIGEN)
-	# Use generic Eigen include paths e.g. <Eigen/Core>
-	set(GTSAM_EIGEN_INCLUDE_PREFIX "")
+	
 
 	find_package(Eigen3 REQUIRED)
 	include_directories(AFTER "${EIGEN3_INCLUDE_DIR}")
 	
+	# Use generic Eigen include paths e.g. <Eigen/Core>
+    set(GTSAM_EIGEN_INCLUDE_PREFIX "${EIGEN3_INCLUDE_DIR}")
+	
 	# check if MKL is also enabled - can have one or the other, but not both!
 	if(EIGEN_USE_MKL_ALL)
 	  message(FATAL_ERROR "MKL cannot be used together with system-installed Eigen, as MKL support relies on patches which are not yet in the system-installed Eigen. Disable either GTSAM_USE_SYSTEM_EIGEN or GTSAM_WITH_EIGEN_MKL")
 	endif()
 else()
 	# Use bundled Eigen include path. 
-	set(GTSAM_EIGEN_INCLUDE_PREFIX "gtsam/3rdparty/Eigen/")
-
 	# Clear any variables set by FindEigen3
 	if(EIGEN3_INCLUDE_DIR)
 		set(EIGEN3_INCLUDE_DIR NOTFOUND CACHE STRING "" FORCE)
 	endif()
 	# Add the bundled version of eigen to the include path so that it can still be included
 	# with  #include <Eigen/Core>
-	include_directories(BEFORE ${GTSAM_EIGEN_INCLUDE_PREFIX})
+	include_directories(BEFORE "gtsam/3rdparty/Eigen/")
+	
+	# set full path, to be used by external projects
+	#  this will be added to GTSAM_INCLUDE_DIR by gtsam_extra.cmake.in
+	set(GTSAM_EIGEN_INCLUDE_PREFIX "${CMAKE_INSTALL_PREFIX}/include/gtsam/3rdparty/Eigen/")
+	
 endif()
 
 # Write Eigen include file with the paths for either the system Eigen or the GTSAM-bundled Eigen
-configure_file(gtsam/3rdparty/gtsam_eigen_includes.h.in gtsam/3rdparty/gtsam_eigen_includes.h)
+#configure_file(gtsam/3rdparty/gtsam_eigen_includes.h.in gtsam/3rdparty/gtsam_eigen_includes.h)
 
 # Install the configuration file for Eigen
-install(FILES ${PROJECT_BINARY_DIR}/gtsam/3rdparty/gtsam_eigen_includes.h DESTINATION include/gtsam/3rdparty)
+#install(FILES ${PROJECT_BINARY_DIR}/gtsam/3rdparty/gtsam_eigen_includes.h DESTINATION include/gtsam/3rdparty)
 
 ###############################################################################
 # Global compile options
diff --git a/gtsam_extra.cmake.in b/gtsam_extra.cmake.in
index 89a97d51b..781b08d57 100644
--- a/gtsam_extra.cmake.in
+++ b/gtsam_extra.cmake.in
@@ -13,6 +13,10 @@ if("@GTSAM_USE_TBB@")
   list(APPEND GTSAM_INCLUDE_DIR "@TBB_INCLUDE_DIRS@")
 endif()
 
+# Append Eigen include path, set in top-level CMakeLists.txt to either
+# system-eigen, or GTSAM eigen path
+list(APPEND GTSAM_INCLUDE_DIR "@GTSAM_EIGEN_INCLUDE_PREFIX@")
+
 if("@GTSAM_USE_EIGEN_MKL@")
   list(APPEND GTSAM_INCLUDE_DIR "@MKL_INCLUDE_DIR@")
 endif()