diff --git a/CMakeLists.txt b/CMakeLists.txt
index 110daa30..839969b6 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -19,7 +19,7 @@ if(WITH_DEBUG_SYMBOLS)
     set(DEBUG_SYMBOL "-g")
 endif()
 
-set(CMAKE_MODULE_PATH ${PROJECT_SOURCE_DIR}/cmake)
+list(APPEND CMAKE_MODULE_PATH "${PROJECT_SOURCE_DIR}/cmake")
 
 include(FindThreads)
 include(FindProtobuf)