diff --git a/c/unix/socket.c b/c/unix/socket.c
index b8946a4..2896c50 100644
--- a/c/unix/socket.c
+++ b/c/unix/socket.c
@@ -235,7 +235,7 @@ s48_accept(s48_value channel)
    * and return #F to tell the Scheme procedure to wait.
    */
 
-  if ((errno != EWOULDBLOCK) && (errno != EINTR) && (errno == EAGAIN))
+  if ((errno != EWOULDBLOCK) && (errno != EINTR) && (errno != EAGAIN))
     s48_raise_os_error(errno);
 
   if (! s48_add_pending_fd(socket_fd, TRUE))