diff --git a/lib/roken/roken-common.h b/lib/roken/roken-common.h
index a819d510d..02122be49 100644
--- a/lib/roken/roken-common.h
+++ b/lib/roken/roken-common.h
@@ -401,6 +401,10 @@ socket_set_debug (rk_socket_t);
 ROKEN_LIB_FUNCTION void ROKEN_LIB_CALL
 socket_set_tos (rk_socket_t, int);
 
+#define socket_set_nonblocking rk_socket_set_nonblocking
+ROKEN_LIB_FUNCTION void ROKEN_LIB_CALL
+socket_set_nonblocking(rk_socket_t, int);
+
 #define socket_set_reuseaddr rk_socket_set_reuseaddr
 ROKEN_LIB_FUNCTION void ROKEN_LIB_CALL
 socket_set_reuseaddr (rk_socket_t, int);
diff --git a/lib/roken/socket.c b/lib/roken/socket.c
index 017d6252e..65aea15b5 100644
--- a/lib/roken/socket.c
+++ b/lib/roken/socket.c
@@ -259,6 +259,29 @@ socket_set_tos (rk_socket_t sock, int tos)
 #endif
 }
 
+/*
+ * Set the non-blocking-ness of the socket.
+ */
+
+ROKEN_LIB_FUNCTION void ROKEN_LIB_CALL
+socket_set_nonblocking(rk_socket_t sock, int nonblock)
+{
+    int flags;
+#if defined(O_NONBLOCK)
+    flags = fcntl(sock, F_GETFL, 0);
+    if (flags == -1)
+	return;
+    if (nonblock)
+	flags |= O_NONBLOCK;
+    else
+	flags &= ~O_NONBLOCK;
+    fcntl(sock, F_SETFL, flags);
+#elif defined(FIOBIO)
+    flags = !!nonblock;
+    return ioctl(sock, FIOBIO, &flags);
+#endif
+}
+
 /*
  * set the reuse of addresses on `sock' to `val'.
  */