diff --git a/usb-linux.c b/usb-linux.c
index 105ce88..88728e9 100644
--- a/usb-linux.c
+++ b/usb-linux.c
@@ -1206,7 +1206,8 @@
         ret = 1;
 #if 0
     } else {
-        monitor_printf(mon, "husb: could not open %s\n", filename);
+        if (mon)
+            monitor_printf(mon, "husb: could not open %s\n", filename);
 #endif
     }
 
@@ -1339,15 +1340,17 @@
         }
     found_devices:
         if (!usb_fs_type) {
-            monitor_printf(mon, "husb: unable to access USB devices\n");
+            if (mon)
+                monitor_printf(mon, "husb: unable to access USB devices\n");
             return -ENOENT;
         }
 
         /* the module setting (used later for opening devices) */
         usb_host_device_path = qemu_mallocz(strlen(devpath)+1);
         strcpy(usb_host_device_path, devpath);
-        monitor_printf(mon, "husb: using %s file-system with %s\n",
-                       fs_type[usb_fs_type], usb_host_device_path);
+        if (mon)
+            monitor_printf(mon, "husb: using %s file-system with %s\n",
+                           fs_type[usb_fs_type], usb_host_device_path);
     }
 
     switch (usb_fs_type) {