diff --git a/src/libsystemd/sd-bus/bus-socket.c b/src/libsystemd/sd-bus/bus-socket.c
index fc7e8e844a..de36a1f278 100644
--- a/src/libsystemd/sd-bus/bus-socket.c
+++ b/src/libsystemd/sd-bus/bus-socket.c
@@ -544,9 +544,11 @@ static int bus_socket_read_auth(sd_bus *b) {
 
         iov = IOVEC_MAKE((uint8_t *)b->rbuffer + b->rbuffer_size, n - b->rbuffer_size);
 
-        if (b->prefer_readv)
+        if (b->prefer_readv) {
                 k = readv(b->input_fd, &iov, 1);
-        else {
+                if (k < 0)
+                        k = -errno;
+        } else {
                 mh = (struct msghdr) {
                         .msg_iov = &iov,
                         .msg_iovlen = 1,
@@ -1187,9 +1189,11 @@ int bus_socket_read_message(sd_bus *bus) {
 
         iov = IOVEC_MAKE((uint8_t *)bus->rbuffer + bus->rbuffer_size, need - bus->rbuffer_size);
 
-        if (bus->prefer_readv)
+        if (bus->prefer_readv) {
                 k = readv(bus->input_fd, &iov, 1);
-        else {
+                if (k < 0)
+                        k = -errno;
+        } else {
                 mh = (struct msghdr) {
                         .msg_iov = &iov,
                         .msg_iovlen = 1,