diff --git a/src/qemu/qemu_blockjob.c b/src/qemu/qemu_blockjob.c
index a991309ee7..80d0269128 100644
--- a/src/qemu/qemu_blockjob.c
+++ b/src/qemu/qemu_blockjob.c
@@ -143,6 +143,12 @@ qemuBlockJobRegister(qemuBlockJobDataPtr job,
 {
     qemuDomainObjPrivatePtr priv = vm->privateData;
 
+    if (disk && QEMU_DOMAIN_DISK_PRIVATE(disk)->blockjob) {
+        virReportError(VIR_ERR_INTERNAL_ERROR,
+                       _("disk '%s' has a blockjob assigned"), disk->dst);
+        return -1;
+    }
+
     if (virHashAddEntry(priv->blockjobs, job->name, virObjectRef(job)) < 0) {
         virObjectUnref(job);
         return -1;