diff --git a/include/iconv.h b/include/iconv.h
index 05e7427a4bf0..a5a830b75fac 100644
--- a/include/iconv.h
+++ b/include/iconv.h
@@ -33,12 +33,10 @@
 #ifndef _ICONV_H_
 #define _ICONV_H_
 
-#include <sys/cdefs.h>
 #include <sys/types.h>
 
 #include <wchar.h>
 
-#include <sys/cdefs.h>
 #include <sys/types.h>
 
 #ifdef __cplusplus
diff --git a/include/mqueue.h b/include/mqueue.h
index 910be7481796..b814c3f1b4ad 100644
--- a/include/mqueue.h
+++ b/include/mqueue.h
@@ -29,7 +29,6 @@
 #ifndef _MQUEUE_H_
 #define _MQUEUE_H_
 
-#include <sys/cdefs.h>
 #include <sys/types.h>
 #include <sys/mqueue.h>
 #include <sys/signal.h>
diff --git a/include/nl_types.h b/include/nl_types.h
index 6ba15132126d..120d1911631f 100644
--- a/include/nl_types.h
+++ b/include/nl_types.h
@@ -34,7 +34,6 @@
 #ifndef _NL_TYPES_H_
 #define _NL_TYPES_H_
 
-#include <sys/cdefs.h>
 #include <sys/types.h>
 
 #ifdef _NLS_PRIVATE
diff --git a/include/sched.h b/include/sched.h
index e03f076febb1..14512559e2a8 100644
--- a/include/sched.h
+++ b/include/sched.h
@@ -29,7 +29,6 @@
 #ifndef __SCHED_H__
 #define __SCHED_H__
 
-#include <sys/cdefs.h>
 #include <sys/types.h>
 #include <sys/sched.h>
 #if __BSD_VISIBLE
diff --git a/include/stringlist.h b/include/stringlist.h
index c4eff6714f41..c0ac84ef8679 100644
--- a/include/stringlist.h
+++ b/include/stringlist.h
@@ -30,7 +30,7 @@
 
 #ifndef _STRINGLIST_H
 #define _STRINGLIST_H 
-#include <sys/cdefs.h>
+
 #include <sys/types.h>
 
 /*
diff --git a/include/unistd.h b/include/unistd.h
index afcb6c0ed700..e3e5675b3da0 100644
--- a/include/unistd.h
+++ b/include/unistd.h
@@ -32,7 +32,6 @@
 #ifndef _UNISTD_H_
 #define	_UNISTD_H_
 
-#include <sys/cdefs.h>
 #include <sys/types.h>			/* XXX adds too much pollution. */
 #include <sys/unistd.h>
 #include <sys/_null.h>