diff --git a/CMakeLists.txt b/CMakeLists.txt
index a0fd3bba..7732075b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -201,8 +201,8 @@ if (ZLIB_FOUND)
   include_directories(${ZLIB_INCLUDE_DIRS})
   target_link_libraries(ixwebsocket ${ZLIB_LIBRARIES})
 else()
-  add_subdirectory(third_party/zlib)
   include_directories(third_party/zlib ${CMAKE_CURRENT_BINARY_DIR}/third_party/zlib)
+  add_subdirectory(third_party/zlib)
   target_link_libraries(ixwebsocket zlibstatic)
 endif()