diff --git a/headers/posix/sys/select.h b/headers/posix/sys/select.h
index 3f41e137ce..87ae4c1554 100644
--- a/headers/posix/sys/select.h
+++ b/headers/posix/sys/select.h
@@ -26,18 +26,10 @@
 
 typedef __haiku_uint32 fd_mask;
 
-#ifndef _howmany
-#	define _howmany(x, y) (((x) + ((y) - 1)) / (y))
-#endif
-
-#ifndef howmany
-#	define howmany(x, y) (((x) + ((y) - 1)) / (y))
-#endif
-
 #define NFDBITS (sizeof(fd_mask) * 8)	/* bits per mask */
 
 typedef struct fd_set {
-	fd_mask bits[_howmany(FD_SETSIZE, NFDBITS)];
+	fd_mask bits[((FD_SETSIZE) + ((NFDBITS) - 1)) / (NFDBITS)];
 } fd_set;
 
 #define _FD_BITSINDEX(fd) ((fd) / NFDBITS)
@@ -54,6 +46,7 @@ typedef struct fd_set {
 
 #endif	/* FD_SET */
 
+
 #ifdef __cplusplus
 extern "C" {
 #endif