diff --git a/cmake/targets/BuildBun.cmake b/cmake/targets/BuildBun.cmake
index 622ed19825..d7b5e88867 100644
--- a/cmake/targets/BuildBun.cmake
+++ b/cmake/targets/BuildBun.cmake
@@ -824,6 +824,7 @@ if(WIN32)
 endif()
 
 target_compile_definitions(${bun} PRIVATE
+  # This is needed for dladdr in dlfcn.h, all libc's add it if you do #define _GNU_SOURCE
   _GNU_SOURCE
   _HAS_EXCEPTIONS=0
   LIBUS_USE_OPENSSL=1