diff --git a/CHANGES b/CHANGES
index f3e85ae..4a62c64 100644
--- a/CHANGES
+++ b/CHANGES
@@ -20,6 +20,7 @@
   apending 0 bytes to an empty array would fail it
   remove socket_sendfile now that we have io_sendfile
   break out alloca #include dependency into havealloca.h
+  support HP-UX sendfile64 (thanks to Rolf Eike Beer)
 
 0.16:
   add buffer_fromsa (make buffer from stralloc)
diff --git a/GNUmakefile b/GNUmakefile
index 928301f..e7f8533 100644
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -80,7 +80,7 @@ $(DNS_OBJS): dns.h stralloc.h taia.h tai.h uint64.h iopause.h
 $(CASE_OBJS): case.h
 $(ARRAY_OBJS): uint64.h array.h
 $(MULT_OBJS): uint64.h uint32.h uint16.h safemult.h
-$(IO_OBJS): uint64.h array.h io.h io_internal.h taia.h tai.h haveepoll.h havekqueue.h havesigio.h havebsdsf.h havedevpoll.h
+$(IO_OBJS): uint64.h array.h io.h io_internal.h taia.h tai.h haveepoll.h havekqueue.h havesigio.h havebsdsf.h havedevpoll.h havesendfile.h
 
 
 iob_addbuf.o iob_addfile.o iob_new.o iob_reset.o iob_send.o: iob_internal.h iob.h
@@ -137,11 +137,12 @@ t: t.o libowfat.a
 clean:
 	rm -f *.o *.a *.da *.bbg *.bb core t haveip6.h haven2i.h \
 havesl.h haveinline.h iopause.h select.h havekqueue.h haveepoll.h \
-libepoll havesigio.h havebsdsf.h havescope.h havedevpoll.h Makefile dep
+libepoll havesigio.h havebsdsf.h havesendfile.h havescope.h havedevpoll.h \
+Makefile dep
 
 INCLUDES=buffer.h byte.h fmt.h ip4.h ip6.h mmap.h scan.h socket.h str.h stralloc.h \
 uint16.h uint32.h uint64.h open.h textcode.h tai.h taia.h dns.h iopause.h case.h \
-openreadclose.h readclose.h ndelay.h array.h io.h safemult.h iob.h
+openreadclose.h readclose.h ndelay.h array.h io.h safemult.h iob.h havealloca.h
 
 install: libowfat.a
 	install -d $(INCLUDEDIR) $(MAN3DIR) $(LIBDIR)
@@ -199,6 +200,11 @@ havebsdsf.h: trybsdsf.c
 	if $(DIET) $(CC) $(CFLAGS) -c trybsdsf.c >/dev/null 2>&1; then echo "#define HAVE_BSDSENDFILE"; fi > $@
 	-rm -f trybsdsf.o
 
+havesendfile.h: trysendfile.c
+	-rm -f $@
+	if $(DIET) $(CC) $(CFLAGS) -c trysendfile.c >/dev/null 2>&1; then echo "#define HAVE_SENDFILE"; fi > $@
+	-rm -f trysendfile.o
+
 haveepoll.h: tryepoll.c
 	-rm -f $@
 	if $(DIET) $(CC) $(CFLAGS) -o tryepoll tryepoll.c >/dev/null 2>&1; then echo "#define HAVE_EPOLL 1"; else \
diff --git a/io/io_sendfile.c b/io/io_sendfile.c
index defc33a..1f6a1d8 100644
--- a/io/io_sendfile.c
+++ b/io/io_sendfile.c
@@ -2,6 +2,7 @@
 #define _FILE_OFFSET_BITS 64
 #include "io_internal.h"
 #include "havebsdsf.h"
+#include "havesendfile.h"
 
 #if defined(HAVE_BSDSENDFILE)
 #include <sys/types.h>
@@ -40,6 +41,19 @@ int64 io_sendfile(int64 s,int64 fd,uint64 off,uint64 n) {
   return i;
 }
 
+#elif defined(HAVE_SENDFILE)
+
+#ifdef __hpux__
+
+#include <sys/types.h>
+#include <sys/uio.h>
+#include <sys/socket.h>
+
+int64 io_sendfile(int64 out,int64 in,uint64 off,uint64 bytes) {
+  return sendfile64(out,in,off,bytes,0,0);
+}
+#endif
+
 #else
 
 #include <unistd.h>
diff --git a/trysendfile.c b/trysendfile.c
new file mode 100644
index 0000000..13c3e86
--- /dev/null
+++ b/trysendfile.c
@@ -0,0 +1,24 @@
+#ifdef __hpux__
+#include <sys/types.h>
+#include <sys/uio.h>
+#include <sys/socket.h>
+
+int main() {
+/*
+      sbsize_t sendfile(int s, int fd, off_t offset, bsize_t nbytes,
+                    const struct iovec *hdtrl, int flags);
+*/
+  struct iovec x[2];
+  int fd=open("havesendfile.c",0);
+  x[0].iov_base="header";
+  x[0].iov_len=6;
+  x[1].iov_base="footer";
+  x[1].iov_len=6;
+  sendfile(1 /* dest socket */,fd /* src file */,
+           0 /* offset */, 23 /* nbytes */,
+           x, 0);
+  perror("sendfile");
+}
+#else
+#error unsupported architecture
+#endif