diff --git a/qemu-io.c b/qemu-io.c
index 8e38b28..8074656 100644
--- a/qemu-io.c
+++ b/qemu-io.c
@@ -230,13 +230,14 @@ static int open_f(BlockBackend *blk, int argc, char **argv)
     qemu_opts_reset(&empty_opts);

     if (optind == argc - 1) {
-        return openfile(argv[optind], flags, writethrough, force_share, opts);
+        openfile(argv[optind], flags, writethrough, force_share, opts);
     } else if (optind == argc) {
-        return openfile(NULL, flags, writethrough, force_share, opts);
+        openfile(NULL, flags, writethrough, force_share, opts);
     } else {
         QDECREF(opts);
-        return qemuio_command_usage(&open_cmd);
+        qemuio_command_usage(&open_cmd);
     }
+    return 0;
 }

 static int quit_f(BlockBackend *blk, int argc, char **argv)
diff --git a/tests/qemu-iotests/060.out b/tests/qemu-iotests/060.out
index 3bc1461..5ca3af4 100644
--- a/tests/qemu-iotests/060.out
+++ b/tests/qemu-iotests/060.out
@@ -21,6 +21,7 @@ Format specific information:
     refcount bits: 16
     corrupt: true
 can't open device TEST_DIR/t.IMGFMT: IMGFMT: Image is corrupt; cannot be opened read/write
+no file open, try 'help open'
 read 512/512 bytes at offset 0
 512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)

diff --git a/tests/qemu-iotests/114.out b/tests/qemu-iotests/114.out
index b6d10e4..1a47a52 100644
--- a/tests/qemu-iotests/114.out
+++ b/tests/qemu-iotests/114.out
@@ -1,6 +1,6 @@
 QA output created by 114
-Formatting 'TEST_DIR/t.IMGFMT.base', fmt=IMGFMT size=67108864 
-Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 backing_file=TEST_DIR/t.IMGFMT.base 
+Formatting 'TEST_DIR/t.IMGFMT.base', fmt=IMGFMT size=67108864
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 backing_file=TEST_DIR/t.IMGFMT.base
 image: TEST_DIR/t.IMGFMT
 file format: IMGFMT
 virtual size: 64M (67108864 bytes)
@@ -8,6 +8,7 @@ cluster_size: 65536
 backing file: TEST_DIR/t.IMGFMT.base
 backing file format: foo
 can't open device TEST_DIR/t.qcow2: Could not open backing file: Unknown driver 'foo'
+no file open, try 'help open'
 read 4096/4096 bytes at offset 0
 4 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 *** done
diff --git a/tests/qemu-iotests/153.out b/tests/qemu-iotests/153.out
index 5ba0b63..5b917b1 100644
--- a/tests/qemu-iotests/153.out
+++ b/tests/qemu-iotests/153.out
@@ -33,10 +33,12 @@ Is another process using the image?
 _qemu_io_wrapper -c open  TEST_DIR/t.qcow2 -c read 0 512
 can't open device TEST_DIR/t.qcow2: Failed to get "write" lock
 Is another process using the image?
+no file open, try 'help open'

 _qemu_io_wrapper -c open -r  TEST_DIR/t.qcow2 -c read 0 512
 can't open device TEST_DIR/t.qcow2: Failed to get shared "write" lock
 Is another process using the image?
+no file open, try 'help open'

 _qemu_img_wrapper info TEST_DIR/t.qcow2
 qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get shared "write" lock
@@ -99,6 +101,7 @@ _qemu_io_wrapper -U -r -c read 0 512 TEST_DIR/t.qcow2

 _qemu_io_wrapper -c open -U TEST_DIR/t.qcow2 -c read 0 512
 can't open device TEST_DIR/t.qcow2: force-share=on can only be used with read-only images
+no file open, try 'help open'

 _qemu_io_wrapper -c open -r -U TEST_DIR/t.qcow2 -c read 0 512

@@ -166,6 +169,7 @@ _qemu_io_wrapper -r -c read 0 512 TEST_DIR/t.qcow2
 _qemu_io_wrapper -c open  TEST_DIR/t.qcow2 -c read 0 512
 can't open device TEST_DIR/t.qcow2: Failed to get "write" lock
 Is another process using the image?
+no file open, try 'help open'

 _qemu_io_wrapper -c open -r  TEST_DIR/t.qcow2 -c read 0 512

@@ -214,6 +218,7 @@ _qemu_io_wrapper -U -r -c read 0 512 TEST_DIR/t.qcow2

 _qemu_io_wrapper -c open -U TEST_DIR/t.qcow2 -c read 0 512
 can't open device TEST_DIR/t.qcow2: force-share=on can only be used with read-only images
+no file open, try 'help open'

 _qemu_io_wrapper -c open -r -U TEST_DIR/t.qcow2 -c read 0 512

@@ -313,6 +318,7 @@ _qemu_io_wrapper -U -r -c read 0 512 TEST_DIR/t.qcow2

 _qemu_io_wrapper -c open -U TEST_DIR/t.qcow2 -c read 0 512
 can't open device TEST_DIR/t.qcow2: force-share=on can only be used with read-only images
+no file open, try 'help open'

 _qemu_io_wrapper -c open -r -U TEST_DIR/t.qcow2 -c read 0 512

