diff --git a/Lagom/CMakeLists.txt b/Lagom/CMakeLists.txt
index a96bb6b3a8..ac94f5ac77 100644
--- a/Lagom/CMakeLists.txt
+++ b/Lagom/CMakeLists.txt
@@ -1,7 +1,7 @@
 cmake_minimum_required (VERSION 3.0)
 project (Lagom)
 
-set(CMAKE_CXX_FLAGS "-O2 -Wall -Wextra -Werror -std=c++17 -fPIC")
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -O2 -Wall -Wextra -Werror -std=c++17 -fPIC")
 
 if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang")
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wconsumed")