diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7bbf8d6..617ac93 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -247,13 +247,10 @@ list(REMOVE_ITEM APP_SOURCES
 list(REMOVE_ITEM APP_SOURCES "${CMAKE_CURRENT_SOURCE_DIR}/src/CoolPropLib.cpp")
 
 set(APP_INCLUDE_DIRS "${CMAKE_CURRENT_SOURCE_DIR}")
-list(APPEND APP_INCLUDE_DIRS "${CMAKE_CURRENT_SOURCE_DIR}/externals/Eigen")
-list(APPEND APP_INCLUDE_DIRS
-     "${CMAKE_CURRENT_SOURCE_DIR}/externals/msgpack-c/include")
-list(APPEND APP_INCLUDE_DIRS
-     "${CMAKE_CURRENT_SOURCE_DIR}/externals/fmtlib/include")
-list(APPEND APP_INCLUDE_DIRS "${CMAKE_CURRENT_SOURCE_DIR}/externals/fmtlib"
-)# should be deprecated
+find_package(Eigen3 CONFIG REQUIRED)
+find_package(msgpack-cxx CONFIG REQUIRED)
+find_package(fmt CONFIG REQUIRED)
+link_libraries(Eigen3::Eigen msgpack-cxx fmt::fmt)
 list(APPEND APP_INCLUDE_DIRS "${CMAKE_CURRENT_SOURCE_DIR}/include")
 list(APPEND APP_INCLUDE_DIRS "${CMAKE_CURRENT_SOURCE_DIR}/src")