diff --git a/src/box/iproto.cc b/src/box/iproto.cc
index 7c11d05b370fa4819e0ec6d78ec85b9b972e1a17..89b8547b4a126c3a64144fa2f7ce735ed69da469 100644
--- a/src/box/iproto.cc
+++ b/src/box/iproto.cc
@@ -859,6 +859,8 @@ iproto_connection_on_input(ev_loop *loop, struct ev_io *watcher,
 		/* Read input. */
 		int nrd = sio_read(fd, in->wpos, ibuf_unused(in));
 		if (nrd < 0) {                  /* Socket is not ready. */
+			if (! sio_wouldblock(errno))
+				diag_raise();
 			ev_io_start(loop, &con->input);
 			return;
 		}
diff --git a/src/coio.cc b/src/coio.cc
index 245376285ebbc7d79b4d2894f26956da8577c03f..51596e9eaf274f1217168fc1352dcf3c95f67d5e 100644
--- a/src/coio.cc
+++ b/src/coio.cc
@@ -316,6 +316,8 @@ coio_read_ahead_timeout(struct ev_io *coio, void *buf, size_t sz,
 		} else if (nrd == 0) {
 			errno = 0;
 			return sz - to_read;
+		} else if (! sio_wouldblock(errno)) {
+			diag_raise();
 		}
 
 		/* The socket is not ready, yield */
@@ -407,6 +409,8 @@ coio_write_timeout(struct ev_io *coio, const void *buf, size_t sz,
 				return sz;
 			towrite -= nwr;
 			buf = (char *) buf + nwr;
+		} else if (nwr < 0 && !sio_wouldblock(errno)) {
+			diag_raise();
 		}
 		if (! ev_is_active(coio)) {
 			ev_io_set(coio, coio->fd, EV_WRITE);
diff --git a/src/sio.cc b/src/sio.cc
index e1ad1c12988fb4d4826ba740ca5986e9a7f71267..e8d2416d50837f4daf809d0c4eb33cb32d00f079 100644
--- a/src/sio.cc
+++ b/src/sio.cc
@@ -232,7 +232,7 @@ sio_read(int fd, void *buf, size_t count)
 			errno = 0;
 			n = 0;
 		} else {
-			tnt_raise(SocketError, sio_socketname(fd),
+			diag_set(SocketError, sio_socketname(fd),
 				  "read(%zd)", count);
 		}
 	}
@@ -244,7 +244,7 @@ sio_write(int fd, const void *buf, size_t count)
 {
 	ssize_t n = write(fd, buf, count);
 	if (n < 0 && !sio_wouldblock(errno))
-		tnt_raise(SocketError, sio_socketname(fd), "write(%zd)", count);
+		diag_set(SocketError, sio_socketname(fd), "write(%zd)", count);
 	return n;
 }