diff --git a/hw/esp.c b/hw/esp.c
index a864af3..ade99dc 100644
--- a/hw/esp.c
+++ b/hw/esp.c
@@ -390,10 +390,9 @@ static void esp_do_dma(ESPState *s)
     }
 }
 
-static void esp_command_complete(SCSIBus *bus, int reason, SCSIRequest *req,
-                                 uint32_t arg)
+static void esp_command_complete(SCSIRequest *req, int reason, uint32_t arg)
 {
-    ESPState *s = DO_UPCAST(ESPState, busdev.qdev, bus->qbus.parent);
+    ESPState *s = DO_UPCAST(ESPState, busdev.qdev, req->bus->qbus.parent);
 
     if (reason == SCSI_REASON_DONE) {
         DPRINTF("SCSI Command complete\n");
diff --git a/hw/lsi53c895a.c b/hw/lsi53c895a.c
index 186b87a..6191a64 100644
--- a/hw/lsi53c895a.c
+++ b/hw/lsi53c895a.c
@@ -688,10 +688,9 @@ static int lsi_queue_tag(LSIState *s, uint32_t tag, uint32_t arg)
 }
 
 /* Callback to indicate that the SCSI layer has completed a transfer.  */
-static void lsi_command_complete(SCSIBus *bus, int reason, SCSIRequest *req,
-                                 uint32_t arg)
+static void lsi_command_complete(SCSIRequest *req, int reason, uint32_t arg)
 {
-    LSIState *s = DO_UPCAST(LSIState, dev.qdev, bus->qbus.parent);
+    LSIState *s = DO_UPCAST(LSIState, dev.qdev, req->bus->qbus.parent);
     int out;
 
     out = (s->sstat1 & PHASE_MASK) == PHASE_DO;
diff --git a/hw/scsi-bus.c b/hw/scsi-bus.c
index bb88a56..0f8fd57 100644
--- a/hw/scsi-bus.c
+++ b/hw/scsi-bus.c
@@ -594,6 +594,5 @@ void scsi_req_complete(SCSIRequest *req)
 {
     assert(req->status != -1);
     scsi_req_dequeue(req);
-    req->bus->complete(req->bus, SCSI_REASON_DONE,
-                       req, req->status);
+    req->bus->complete(req, SCSI_REASON_DONE, req->status);
 }
diff --git a/hw/scsi-disk.c b/hw/scsi-disk.c
index 1541524..4353aaf 100644
--- a/hw/scsi-disk.c
+++ b/hw/scsi-disk.c
@@ -166,7 +166,7 @@ static void scsi_read_complete(void * opaque, int ret)
 
     DPRINTF("Data ready tag=0x%x len=%zd\n", r->req.tag, iov_len);
 
-    r->req.bus->complete(r->req.bus, SCSI_REASON_DATA, &r->req, iov_len);
+    r->req.bus->complete(&r->req, SCSI_REASON_DATA, iov_len);
 }
 
 
@@ -186,7 +186,7 @@ static void scsi_read_data(SCSIRequest *req)
     if (r->sector_count == (uint32_t)-1) {
         DPRINTF("Read buf_len=%zd\n", r->iov[0].iov_len);
         r->sector_count = 0;
-        r->req.bus->complete(r->req.bus, SCSI_REASON_DATA, &r->req,
+        r->req.bus->complete(&r->req, SCSI_REASON_DATA,
                              r->iov[0].iov_len);
         return;
     }
@@ -236,7 +236,7 @@ static int scsi_handle_rw_error(SCSIDiskReq *r, int error, int type)
         vm_stop(0);
     } else {
         if (type == SCSI_REQ_STATUS_RETRY_READ) {
-            r->req.bus->complete(r->req.bus, SCSI_REASON_DATA, &r->req, 0);
+            r->req.bus->complete(&r->req, SCSI_REASON_DATA, 0);
         }
         if (error == EBADR) {
                 scsi_command_complete(r, CHECK_CONDITION,
@@ -280,7 +280,7 @@ static void scsi_write_complete(void * opaque, int ret)
             r->iov[0].iov_len = len;
         }
         DPRINTF("Write complete tag=0x%x more=%d\n", r->req.tag, len);
-        r->req.bus->complete(r->req.bus, SCSI_REASON_DATA, &r->req, len);
+        r->req.bus->complete(&r->req, SCSI_REASON_DATA, len);
     }
 }
 
diff --git a/hw/scsi-generic.c b/hw/scsi-generic.c
index 6250ce5..f7cf67d 100644
--- a/hw/scsi-generic.c
+++ b/hw/scsi-generic.c
@@ -192,7 +192,7 @@ static void scsi_read_complete(void * opaque, int ret)
     DPRINTF("Data ready tag=0x%x len=%d\n", r->req.tag, len);
 
     r->len = -1;
-    r->req.bus->complete(r->req.bus, SCSI_REASON_DATA, &r->req, len);
+    r->req.bus->complete(&r->req, SCSI_REASON_DATA, len);
     if (len == 0)
         scsi_command_complete(r, 0);
 }
@@ -222,7 +222,7 @@ static void scsi_read_data(SCSIRequest *req)
         DPRINTF("Sense: %d %d %d %d %d %d %d %d\n",
                 r->buf[0], r->buf[1], r->buf[2], r->buf[3],
                 r->buf[4], r->buf[5], r->buf[6], r->buf[7]);
-        r->req.bus->complete(r->req.bus, SCSI_REASON_DATA, &r->req, s->senselen);
+        r->req.bus->complete(&r->req, SCSI_REASON_DATA, s->senselen);
         /* Clear sensebuf after REQUEST_SENSE */
         scsi_clear_sense(s);
         return;
@@ -268,7 +268,7 @@ static int scsi_write_data(SCSIRequest *req)
 
     if (r->len == 0) {
         r->len = r->buflen;
-        r->req.bus->complete(r->req.bus, SCSI_REASON_DATA, &r->req, r->len);
+        r->req.bus->complete(&r->req, SCSI_REASON_DATA, r->len);
         return 0;
     }
 
diff --git a/hw/scsi.h b/hw/scsi.h
index fbef736..a41f53e 100644
--- a/hw/scsi.h
+++ b/hw/scsi.h
@@ -18,8 +18,7 @@ typedef struct SCSIBus SCSIBus;
 typedef struct SCSIDevice SCSIDevice;
 typedef struct SCSIDeviceInfo SCSIDeviceInfo;
 typedef struct SCSIRequest SCSIRequest;
-typedef void (*scsi_completionfn)(SCSIBus *bus, int reason, SCSIRequest *req,
-                                  uint32_t arg);
+typedef void (*scsi_completionfn)(SCSIRequest *req, int reason, uint32_t arg);
 
 enum SCSIXferMode {
     SCSI_XFER_NONE,      /*  TEST_UNIT_READY, ...            */
diff --git a/hw/usb-msd.c b/hw/usb-msd.c
index ad7d9a7..a60ceeb 100644
--- a/hw/usb-msd.c
+++ b/hw/usb-msd.c
@@ -174,10 +174,9 @@ static void usb_msd_send_status(MSDState *s)
     memcpy(s->usb_buf, &csw, 13);
 }
 
-static void usb_msd_command_complete(SCSIBus *bus, int reason, SCSIRequest *req,
-                                     uint32_t arg)
+static void usb_msd_command_complete(SCSIRequest *req, int reason, uint32_t arg)
 {
-    MSDState *s = DO_UPCAST(MSDState, dev.qdev, bus->qbus.parent);
+    MSDState *s = DO_UPCAST(MSDState, dev.qdev, req->bus->qbus.parent);
     USBPacket *p = s->packet;
 
     if (req->tag != s->tag) {
