diff --git a/tests/qemu-iotests/common.nbd b/tests/qemu-iotests/common.nbd
index 27357f3151..9f841ab402 100644
--- a/tests/qemu-iotests/common.nbd
+++ b/tests/qemu-iotests/common.nbd
@@ -37,11 +37,19 @@ function nbd_server_stop()
 
 function nbd_server_wait_for_unix_socket()
 {
+    pid=$1
+
     for ((i = 0; i < 300; i++))
     do
         if [ -r "$nbd_unix_socket" ]; then
             return
         fi
+        kill -s 0 $pid 2>/dev/null
+        if test $? != 0
+        then
+            echo "qemu-nbd unexpectedly quit"
+            exit 1
+        fi
         sleep 0.1
     done
     echo "Failed in check of unix socket created by qemu-nbd"
@@ -52,5 +60,5 @@ function nbd_server_start_unix_socket()
 {
     nbd_server_stop
     $QEMU_NBD -v -t -k "$nbd_unix_socket" "$@" &
-    nbd_server_wait_for_unix_socket
+    nbd_server_wait_for_unix_socket $!
 }