diff --git a/Makefile b/Makefile
index 0ce4b3253..f055a0827 100644
--- a/Makefile
+++ b/Makefile
@@ -309,10 +309,11 @@ ifeq ($(TARGET),osx)
   USE_TPROXY     = implicit
 else
 ifeq ($(TARGET),openbsd)
-  # This is for OpenBSD >= 3.0
+  # This is for OpenBSD >= 5.7
   USE_POLL       = implicit
   USE_KQUEUE     = implicit
   USE_TPROXY     = implicit
+  USE_ACCEPT4    = implicit
 else
 ifeq ($(TARGET),netbsd)
   # This is for NetBSD
diff --git a/README b/README
index 16982e14d..074a3b0f4 100644
--- a/README
+++ b/README
@@ -43,7 +43,7 @@ and assign it to the TARGET variable :
   - freebsd     for FreeBSD 5 to 10 (others untested)
   - netbsd      for NetBSD
   - osx         for Mac OS/X
-  - openbsd     for OpenBSD 3.1 and above
+  - openbsd     for OpenBSD 5.7 and above
   - aix51       for AIX 5.1
   - aix52       for AIX 5.2
   - cygwin      for Cygwin