diff --git a/qemu-io.c b/qemu-io.c
index 3b3340a..4d0e9f6 100644
--- a/qemu-io.c
+++ b/qemu-io.c
@@ -57,8 +57,13 @@ static int openfile(char *name, int flags, int growable, QDict *opts)
 
     if (growable) {
         if (bdrv_file_open(&qemuio_bs, name, opts, flags, &local_err)) {
-            fprintf(stderr, "%s: can't open device %s: %s\n", progname, name,
-                    error_get_pretty(local_err));
+            if (name) {
+                fprintf(stderr, "%s: can't open device %s: %s\n", progname,
+                        name, error_get_pretty(local_err));
+            } else {
+                fprintf(stderr, "%s: can't open device: %s\n", progname,
+                        error_get_pretty(local_err));
+            }
             error_free(local_err);
             return 1;
         }
@@ -66,8 +71,13 @@ static int openfile(char *name, int flags, int growable, QDict *opts)
         qemuio_bs = bdrv_new("hda");
 
         if (bdrv_open(qemuio_bs, name, opts, flags, NULL, &local_err) < 0) {
-            fprintf(stderr, "%s: can't open device %s: %s\n", progname, name,
-                    error_get_pretty(local_err));
+            if (name) {
+                fprintf(stderr, "%s: can't open device %s: %s\n", progname,
+                        name, error_get_pretty(local_err));
+            } else {
+                fprintf(stderr, "%s: can't open device: %s\n", progname,
+                        error_get_pretty(local_err));
+            }
             error_free(local_err);
             bdrv_unref(qemuio_bs);
             qemuio_bs = NULL;
@@ -127,6 +137,7 @@ static int open_f(BlockDriverState *bs, int argc, char **argv)
     int c;
     QemuOpts *qopts;
     QDict *opts = NULL;
+    char *filename = NULL;
 
     while ((c = getopt(argc, argv, "snrgo:")) != EOF) {
         switch (c) {
@@ -160,11 +171,13 @@ static int open_f(BlockDriverState *bs, int argc, char **argv)
         flags |= BDRV_O_RDWR;
     }
 
-    if (optind != argc - 1) {
+    if (optind == argc - 1) {
+        filename = argv[optind];
+    } else if (optind < argc - 1) {
         return qemuio_command_usage(&open_cmd);
     }
 
-    return openfile(argv[optind], flags, growable, opts);
+    return openfile(filename, flags, growable, opts);
 }
 
 static int quit_f(BlockDriverState *bs, int argc, char **argv)