diff --git a/ext/Makefile.ext.in b/ext/Makefile.ext.in
index 0fd21c5..9b1a505 100644
--- a/ext/Makefile.ext.in
+++ b/ext/Makefile.ext.in
@@ -19,7 +19,7 @@ DESTDIR      =
 CC           = @CC@
 AR           = @AR@
 LOCAL_LFLAGS = @LOCAL_LIB@
-LIBS         = $(XLIBS) @LIBS@
+LIBS         = $(XLIBS) @LIBS@ -lpthread
 CFLAGS       = @CFLAGS@ @SHLIB_SO_CFLAGS@ $(XCFLAGS)
 CPPFLAGS     = @CPPFLAGS@ $(XCPPFLAGS)
 LDFLAGS      = $(LOCAL_LFLAGS) $(XLDFLAGS) @SHLIB_SO_LDFLAGS@
diff --git a/ext/net/gauche-net.h b/ext/net/gauche-net.h
index 7377a36..e9b1a4d 100644
--- a/ext/net/gauche-net.h
+++ b/ext/net/gauche-net.h
@@ -94,7 +94,7 @@ const char *inet_ntop(int af, const void *src, char *dst, socklen_t size);
  * Sockaddr_storage
  */
 
-#if !defined(HAVE_STRUCT_SOCKADDR_STORAGE) && !defined(_MSC_VER)
+#if !defined(HAVE_STRUCT_SOCKADDR_STORAGE) && !defined(_MSC_VER) && !defined(__OpenBSD__)
 /* Alternative implementation in case the system doesn't provide
    sockaddr_storage.  The code is based on the reference implementation
    provided in RFC3493.
diff --git a/ext/net/net.c b/ext/net/net.c
index 7b4ff02..7eeec2c 100644
--- a/ext/net/net.c
+++ b/ext/net/net.c
@@ -35,6 +35,10 @@
 #include <fcntl.h>
 #include <gauche/extend.h>
 
+#ifdef __OpenBSD__
+#include <sys/uio.h>
+#endif
+
 /*==================================================================
  * Socket
  */