--- a/src/string.c	Wed Dec 17 19:05:50 2025 +0100
+++ b/src/string.c	Wed Dec 17 20:13:08 2025 +0100
@@ -25,9 +25,9 @@
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGE.
  */
-#ifdef MEMRCHR_NEED_GNU
+
+// for memrchr in glibc
 #define _GNU_SOURCE
-#endif
 
 #include "cx/string.h"