diff --git a/src/os_unixx.h b/src/os_unixx.h
index c83ea31..edf7914 100644
--- a/src/os_unixx.h
+++ b/src/os_unixx.h
@@ -69,16 +69,7 @@
 #endif
 
 #ifdef HAVE_SYS_SYSTEMINFO_H
-/*
- * foolish Sinix <sys/systeminfo.h> uses SYS_NMLN but doesn't include
- * <limits.h>, where it is defined. Perhaps other systems have the same
- * problem? Include it here. -- Slootman
- */
-# if defined(HAVE_LIMITS_H) && !defined(_LIMITS_H)
-#  include <limits.h>		/* for SYS_NMLN (Sinix 5.41 / Unix SysV.4) */
-# endif
-
-/* Define SYS_NMLN ourselves if it still isn't defined (for CrayT3E). */
+/* <sys/systeminfo.h> uses SYS_NMLN but it may not be defined (CrayT3E). */
 # ifndef SYS_NMLN
 #  define SYS_NMLN 32
 # endif