diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index d91a93504a..6627a3c6b9 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -11631,7 +11631,6 @@ qemuDomainDiskLookupByNodename(virDomainDefPtr def,
  */
 char *
 qemuDomainDiskBackingStoreGetName(virDomainDiskDefPtr disk,
-                                  virStorageSourcePtr src G_GNUC_UNUSED,
                                   unsigned int idx)
 {
     char *ret = NULL;
diff --git a/src/qemu/qemu_domain.h b/src/qemu/qemu_domain.h
index bb9b414a46..132c022246 100644
--- a/src/qemu/qemu_domain.h
+++ b/src/qemu/qemu_domain.h
@@ -973,7 +973,6 @@ virDomainDiskDefPtr qemuDomainDiskLookupByNodename(virDomainDefPtr def,
                                                    unsigned int *idx);
 
 char *qemuDomainDiskBackingStoreGetName(virDomainDiskDefPtr disk,
-                                        virStorageSourcePtr src,
                                         unsigned int idx);
 
 virStorageSourcePtr qemuDomainGetStorageSourceByDevstr(const char *devstr,
diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index af060b3180..31a8090a99 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -1514,7 +1514,7 @@ qemuProcessHandleBlockThreshold(qemuMonitorPtr mon G_GNUC_UNUSED,
         if (virStorageSourceIsLocalStorage(src))
             path = src->path;
 
-        if ((dev = qemuDomainDiskBackingStoreGetName(disk, src, idx)))
+        if ((dev = qemuDomainDiskBackingStoreGetName(disk, idx)))
             event = virDomainEventBlockThresholdNewFromObj(vm, dev, path,
                                                            threshold, excess);
     }