diff --git a/README.md b/README.md
index bfdcd43..b8dd4b9 100644
--- a/README.md
+++ b/README.md
@@ -82,6 +82,7 @@ You can change the build process with a list of different options that you can p
 * `-DENABLE_CJSON_TESTS=On`: Enable building the tests. (on by default)
 * `-DENABLE_CJSON_UTILS=On`: Enable building cJSON_Utils. (off by default)
 * `-DENABLE_TARGET_EXPORT=On`: Enable the export of CMake targets. Turn off if it makes problems. (on by default)
+* `-DENABLE_CUSTOM_COMPILER_FLAGS=On`: Enable custom compiler flags (currently for Clang and GCC). Turn off if it makes problems. (on by default)
 * `-DBUILD_SHARED_LIBS=On`: Build the shared libraries. (on by default)
 * `-DCMAKE_INSTALL_PREFIX=/usr`: Set a prefix for the installation.