Index: eigen-3.4.0/CMakeLists.txt
===================================================================
--- eigen-3.4.0.orig/CMakeLists.txt
+++ eigen-3.4.0/CMakeLists.txt
@@ -466,6 +466,11 @@ install(FILES
   DESTINATION ${INCLUDE_INSTALL_DIR} COMPONENT Devel
   )
 
+install(FILES
+  cmake/FindEigen3.cmake
+  DESTINATION ${CMAKE_INSTALL_PREFIX}/share/cmake/Modules
+  )
+
 if(EIGEN_BUILD_PKGCONFIG)
     configure_file(eigen3.pc.in eigen3.pc @ONLY)
     install(FILES ${CMAKE_CURRENT_BINARY_DIR}/eigen3.pc