diff --git a/CMakeLists.txt b/CMakeLists.txt
index 0af91e392..33cb57946 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -122,7 +122,7 @@ if(NOT WIN32)
 # MSYS2 needs -lssp and -fstack-protector for _FORTIFY_SOURCE
 # macOS with ASAN can't handle _FORTIFY_SOURCE != 1
 if(NOT ${USE_ASAN})
-add_compile_definitions(_FORTIFY_SOURCE=2)
+add_compile_definitions(_FORTIFY_SOURCE=3)
 endif()
 add_compile_options(-Wformat -Werror=format-security)
 endif()