diff --git a/CMakeLists.txt b/CMakeLists.txt
index ab7713135ae..f63f64dc949 100755
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -58,9 +58,6 @@ if(NOT CMAKE_BUILD_TYPE)
     set(CMAKE_BUILD_TYPE "Release" CACHE STRING "Choose the type of build" FORCE)
 endif(NOT CMAKE_BUILD_TYPE)
 
-# relative file paths for use in exceptions
-set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -D__PROJECT_SOURCE_DIR__='\"${PROJECT_SOURCE_DIR}\"'")
-
 set(AERON_THIRDPARTY_BINARY_DIR "${CMAKE_CURRENT_BINARY_DIR}/thirdparty")
 
 ##########################################################
diff --git a/aeron-client/src/main/cpp/CMakeLists.txt b/aeron-client/src/main/cpp/CMakeLists.txt
index 2b379dc39d3..6c3e06469a1 100644
--- a/aeron-client/src/main/cpp/CMakeLists.txt
+++ b/aeron-client/src/main/cpp/CMakeLists.txt
@@ -127,6 +127,11 @@ target_include_directories(aeron_client
     PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}
 )
 
+# relative file paths for use in exceptions
+target_compile_definitions(aeron_client
+    PUBLIC "__PROJECT_SOURCE_DIR__=\"${PROJECT_SOURCE_DIR}\""
+)
+
 if (NOT WIN32)
 	set(CMAKE_THREAD_PREFER_PTHREAD TRUE)
 	set(THREADS_PREFER_PTHREAD_FLAG TRUE)