diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c
index 9f417d27c6..5ca76d2d80 100644
--- a/src/qemu/qemu_monitor_json.c
+++ b/src/qemu/qemu_monitor_json.c
@@ -708,8 +708,15 @@ qemuMonitorJSONHandleIOError(qemuMonitor *mon, virJSONValue *data)
         action = "ignore";
     }
 
-    if ((device = virJSONValueObjectGetString(data, "device")) == NULL)
+    if ((device = virJSONValueObjectGetString(data, "device")) == NULL) {
         VIR_WARN("missing device in disk io error event");
+    } else {
+        /* 'device' was documented as mandatory in the qemu event, but later became
+         * optional, in which case an empty string is sent by qemu. Convert it back
+         * to NULL */
+        if (*device == '\0')
+            device = NULL;
+    }
 
     nodename = virJSONValueObjectGetString(data, "node-name");
 
diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index 34a755a49a..edcd8ac3a8 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -840,9 +840,6 @@ qemuProcessHandleIOError(qemuMonitor *mon G_GNUC_UNUSED,
     virObjectLock(vm);
     priv = QEMU_DOMAIN_PRIVATE(vm);
 
-    if (*diskAlias == '\0')
-        diskAlias = NULL;
-
     if (diskAlias)
         disk = qemuProcessFindDomainDiskByAliasOrQOM(vm, diskAlias, NULL);
     else if (nodename)