diff -ru ksh-openbsd-20180115.orig/history.c ksh-openbsd-20180115/history.c
--- ksh-openbsd-20180115.orig/history.c	2018-01-15 23:04:15.000000000 +0100
+++ ksh-openbsd-20180115/history.c	2018-04-14 15:31:50.346308024 +0200
@@ -28,6 +28,10 @@
 #include "vis.h"
 #include "sh.h"
 
+#ifndef F_EXLCK
+#define F_EXLCK 4
+#endif
+
 #define timespeccmp(tsp, usp, cmp)		\
 	(((tsp)->tv_sec == (usp)->tv_sec) ?	\
 		((tsp)->tv_nsec cmp (usp)->tv_nsec) :	\
diff -ru ksh-openbsd-20180115.orig/Makefile ksh-openbsd-20180115/Makefile
--- ksh-openbsd-20180115.orig/Makefile	2018-01-15 23:04:15.000000000 +0100
+++ ksh-openbsd-20180115/Makefile	2018-04-14 16:03:43.040414391 +0200
@@ -22,12 +22,12 @@
 CDIAGFLAGS+=	-Wshadow
 CDIAGFLAGS+=	-Wdeclaration-after-statement
 
-CFLAGS +=	$(CDIAGFLAGS) `getconf LFS_CFLAGS` -DEMACS -DVI
+CFLAGS +=	$(CDIAGFLAGS) `getconf LFS_CFLAGS` -D_GNU_SOURCE -DEMACS -DVI
 LDADD +=	-lbsd
 
 $(PROG): $(OBJS)
-	$(CC) -o $(PROG) $(CFLAGS) $(LDADD) \
-		$(OBJS)
+	$(CC) -o $(PROG) $(CFLAGS) \
+		$(OBJS) $(LDADD)
 
 all: $(PROG)
 
@@ -37,7 +37,7 @@
 
 install:
 	install -m755 -d $(BINDIR)
-	install -m755 --strip --no-target-directory ksh $(BINDIR)/pdksh
+	install -m755 --no-target-directory ksh $(BINDIR)/pdksh
 	install -m755 -d $(MANDIR)/man1
 	install -m644 --no-target-directory ksh.1 $(MANDIR)/man1/pdksh.1
 	install -m644 --no-target-directory sh.1 $(MANDIR)/man1/pdksh-sh.1
diff -ru ksh-openbsd-20180115.orig/vis.c ksh-openbsd-20180115/vis.c
--- ksh-openbsd-20180115.orig/vis.c	2018-01-15 23:04:15.000000000 +0100
+++ ksh-openbsd-20180115/vis.c	2018-04-14 15:38:41.605684906 +0200
@@ -139,7 +139,7 @@
 	*dst = '\0';
 	return (dst);
 }
-DEF_WEAK(vis);
+//DEF_WEAK(vis);
 
 /*
  * strvis, strnvis, strvisx - visually encode characters from src into dst
@@ -165,7 +165,7 @@
 	*dst = '\0';
 	return (dst - start);
 }
-DEF_WEAK(strvis);
+//DEF_WEAK(strvis);
 
 int
 strnvis(char *dst, const char *src, size_t siz, int flag)