diff --git a/cmake/CMakeLists.txt b/cmake/CMakeLists.txt
index c873429d00..e6ed5be376 100644
--- a/cmake/CMakeLists.txt
+++ b/cmake/CMakeLists.txt
@@ -444,9 +444,9 @@ if(PKG_VORONOI)
     include(ExternalProject)
 
     if(BUILD_SHARED_LIBS)
-      set(VORO_BUILD_OPTIONS CXX="${CMAKE_CXX_COMPILER}" CFLAGS="${CMAKE_POSITION_INDEPENDENT_CODE} ${CMAKE_C_FLAGS}")
+      set(VORO_BUILD_OPTIONS CXX="${CMAKE_CXX_COMPILER}" CFLAGS="${CMAKE_SHARED_LIBRARY_CXX_FLAGS} ${CMAKE_CXX_FLAGS}")
     else()
-      set(VORO_BUILD_OPTIONS CXX="${CMAKE_CXX_COMPILER}" CFLAGS="${CMAKE_C_FLAGS}")
+      set(VORO_BUILD_OPTIONS CXX="${CMAKE_CXX_COMPILER}" CFLAGS="${CMAKE_CXX_FLAGS}")
     endif()
 
     ExternalProject_Add(voro_build