diff --git a/configure.ac b/configure.ac
index ca85e5ed..e1e79ebf 100644
--- a/configure.ac
+++ b/configure.ac
@@ -453,7 +453,7 @@ AC_CHECK_HEADERS([ \
 	fcntl.h io.h \
 	sys/types.h sys/socket.h \
 	unistd.h dlfcn.h \
-	netinet/in.h netinet/in_systm.h \
+	netinet/in.h \
 	netinet/tcp.h arpa/inet.h netdb.h \
 	versionhelpers.h \
 ])
@@ -489,9 +489,6 @@ SOCKET_INCLUDES="
 #ifdef _WIN32
 #include <ws2tcpip.h>
 #endif
-#ifdef HAVE_NETINET_IN_SYSTM_H
-#include <netinet/in_systm.h>
-#endif
 #ifdef HAVE_NETINET_IP_H
 #include <netinet/ip.h>
 #endif
diff --git a/src/openvpn/syshead.h b/src/openvpn/syshead.h
index 53359225..7181b94d 100644
--- a/src/openvpn/syshead.h
+++ b/src/openvpn/syshead.h
@@ -221,10 +221,6 @@
 #include <sys/sockio.h>
 #endif
 
-#ifdef HAVE_NETINET_IN_SYSTM_H
-#include <netinet/in_systm.h>
-#endif
-
 #ifdef HAVE_NETINET_IP_H
 #include <netinet/ip.h>
 #endif
@@ -241,10 +237,6 @@
 #include <sys/uio.h>
 #endif
 
-#ifdef HAVE_NETINET_IN_SYSTM_H
-#include <netinet/in_systm.h>
-#endif
-
 #ifdef HAVE_NETINET_IP_H
 #include <netinet/ip.h>
 #endif
@@ -265,10 +257,6 @@
 #include <sys/uio.h>
 #endif
 
-#ifdef HAVE_NETINET_IN_SYSTM_H
-#include <netinet/in_systm.h>
-#endif
-
 #ifdef HAVE_NETINET_IP_H
 #include <netinet/ip.h>
 #endif
@@ -301,10 +289,6 @@
 #include <sys/uio.h>
 #endif
 
-#ifdef HAVE_NETINET_IN_SYSTM_H
-#include <netinet/in_systm.h>
-#endif
-
 #ifdef HAVE_NETINET_IP_H
 #include <netinet/ip.h>
 #endif