diff --git a/hw/scsi-bus.c b/hw/scsi-bus.c
index d69c74c4ef..b860a09edf 100644
--- a/hw/scsi-bus.c
+++ b/hw/scsi-bus.c
@@ -142,6 +142,7 @@ SCSIRequest *scsi_req_alloc(size_t size, SCSIDevice *d, uint32_t tag, uint32_t l
     req->tag = tag;
     req->lun = lun;
     req->status = -1;
+    req->enqueued = true;
     QTAILQ_INSERT_TAIL(&d->requests, req, next);
     return req;
 }
@@ -158,9 +159,17 @@ SCSIRequest *scsi_req_find(SCSIDevice *d, uint32_t tag)
     return NULL;
 }
 
+static void scsi_req_dequeue(SCSIRequest *req)
+{
+    if (req->enqueued) {
+        QTAILQ_REMOVE(&req->dev->requests, req, next);
+        req->enqueued = false;
+    }
+}
+
 void scsi_req_free(SCSIRequest *req)
 {
-    QTAILQ_REMOVE(&req->dev->requests, req, next);
+    scsi_req_dequeue(req);
     qemu_free(req);
 }
 
@@ -512,6 +521,7 @@ void scsi_req_print(SCSIRequest *req)
 void scsi_req_complete(SCSIRequest *req)
 {
     assert(req->status != -1);
+    scsi_req_dequeue(req);
     req->bus->complete(req->bus, SCSI_REASON_DONE,
                        req->tag,
                        req->status);
diff --git a/hw/scsi.h b/hw/scsi.h
index 4fbf1d5dfd..cb06d6d824 100644
--- a/hw/scsi.h
+++ b/hw/scsi.h
@@ -43,6 +43,7 @@ typedef struct SCSIRequest {
         enum SCSIXferMode mode;
     } cmd;
     BlockDriverAIOCB  *aiocb;
+    bool enqueued;
     QTAILQ_ENTRY(SCSIRequest) next;
 } SCSIRequest;