diff --git a/qemu-io.c b/qemu-io.c
index 269f17c..d47228a 100644
--- a/qemu-io.c
+++ b/qemu-io.c
@@ -57,17 +57,15 @@
     BlockDriverState *bs;
 
     if (qemuio_blk) {
-        fprintf(stderr, "file open already, try 'help close'\n");
+        error_report("file open already, try 'help close'");
         QDECREF(opts);
         return 1;
     }
 
     qemuio_blk = blk_new_open("hda", name, NULL, opts, flags, &local_err);
     if (!qemuio_blk) {
-        fprintf(stderr, "%s: can't open%s%s: %s\n", progname,
-                name ? " device " : "", name ?: "",
-                error_get_pretty(local_err));
-        error_free(local_err);
+        error_reportf_err(local_err, "can't open%s%s: ",
+                          name ? " device " : "", name ?: "");
         return 1;
     }
 
diff --git a/qemu-nbd.c b/qemu-nbd.c
index f9fce4a..99df01f 100644
--- a/qemu-nbd.c
+++ b/qemu-nbd.c
@@ -257,7 +257,7 @@
     fd = open(device, O_RDWR);
     if (fd < 0) {
         /* Linux-only, we can use %m in printf.  */
-        fprintf(stderr, "Failed to open %s: %m\n", device);
+        error_report("Failed to open %s: %m", device);
         goto out_socket;
     }
 
diff --git a/tests/qemu-iotests/059.out b/tests/qemu-iotests/059.out
index 00057fe..d28df5b 100644
--- a/tests/qemu-iotests/059.out
+++ b/tests/qemu-iotests/059.out
@@ -2,17 +2,17 @@
 
 === Testing invalid granularity ===
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-qemu-io: can't open device TEST_DIR/t.vmdk: Invalid granularity, image may be corrupt
+can't open device TEST_DIR/t.vmdk: Invalid granularity, image may be corrupt
 no file open, try 'help open'
 
 === Testing too big L2 table size ===
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-qemu-io: can't open device TEST_DIR/t.vmdk: L2 table size too big
+can't open device TEST_DIR/t.vmdk: L2 table size too big
 no file open, try 'help open'
 
 === Testing too big L1 table size ===
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-qemu-io: can't open device TEST_DIR/t.vmdk: L1 size too big
+can't open device TEST_DIR/t.vmdk: L1 size too big
 no file open, try 'help open'
 
 === Testing monolithicFlat creation and opening ===
@@ -2055,7 +2055,7 @@
 
 === Testing monolithicFlat with internally generated JSON file name ===
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 subformat=monolithicFlat
-qemu-io: can't open: Cannot use relative extent paths with VMDK descriptor file 'json:{"image": {"driver": "file", "filename": "TEST_DIR/t.IMGFMT"}, "driver": "blkdebug", "inject-error.0.event": "read_aio"}'
+can't open: Cannot use relative extent paths with VMDK descriptor file 'json:{"image": {"driver": "file", "filename": "TEST_DIR/t.IMGFMT"}, "driver": "blkdebug", "inject-error.0.event": "read_aio"}'
 
 === Testing version 3 ===
 image: TEST_DIR/iotest-version3.IMGFMT
diff --git a/tests/qemu-iotests/060.out b/tests/qemu-iotests/060.out
index 7511189..5d40206 100644
--- a/tests/qemu-iotests/060.out
+++ b/tests/qemu-iotests/060.out
@@ -20,7 +20,7 @@
     lazy refcounts: false
     refcount bits: 16
     corrupt: true
-qemu-io: can't open device TEST_DIR/t.IMGFMT: IMGFMT: Image is corrupt; cannot be opened read/write
+can't open device TEST_DIR/t.IMGFMT: IMGFMT: Image is corrupt; cannot be opened read/write
 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/069.out b/tests/qemu-iotests/069.out
index c78e8c2..f975856 100644
--- a/tests/qemu-iotests/069.out
+++ b/tests/qemu-iotests/069.out
@@ -4,5 +4,5 @@
 
 Formatting 'TEST_DIR/t.IMGFMT.base', fmt=IMGFMT size=131072
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=131072 backing_file=TEST_DIR/t.IMGFMT.base
-qemu-io: can't open device TEST_DIR/t.IMGFMT: Could not open backing file: Could not open 'TEST_DIR/t.IMGFMT.base': No such file or directory
+can't open device TEST_DIR/t.IMGFMT: Could not open backing file: Could not open 'TEST_DIR/t.IMGFMT.base': No such file or directory
 *** done
diff --git a/tests/qemu-iotests/070.out b/tests/qemu-iotests/070.out
index ca74383..ffd4251 100644
--- a/tests/qemu-iotests/070.out
+++ b/tests/qemu-iotests/070.out
@@ -1,7 +1,7 @@
 QA output created by 070
 
 === Verify open image read-only fails, due to dirty log ===
-qemu-io: can't open device TEST_DIR/iotest-dirtylog-10G-4M.vhdx: VHDX image file 'TEST_DIR/iotest-dirtylog-10G-4M.vhdx' opened read-only, but contains a log that needs to be replayed.  To replay the log, execute:
+can't open device TEST_DIR/iotest-dirtylog-10G-4M.vhdx: VHDX image file 'TEST_DIR/iotest-dirtylog-10G-4M.vhdx' opened read-only, but contains a log that needs to be replayed.  To replay the log, execute:
  qemu-img check -r all 'TEST_DIR/iotest-dirtylog-10G-4M.vhdx': Operation not permitted
  no file open, try 'help open'
 === Verify open image replays log  ===
diff --git a/tests/qemu-iotests/075.out b/tests/qemu-iotests/075.out
index 5f1d6c1..87beae4 100644
--- a/tests/qemu-iotests/075.out
+++ b/tests/qemu-iotests/075.out
@@ -9,30 +9,30 @@
 512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 
 == block_size must be a multiple of 512 ==
-qemu-io: can't open device TEST_DIR/simple-pattern.cloop: block_size 513 must be a multiple of 512
+can't open device TEST_DIR/simple-pattern.cloop: block_size 513 must be a multiple of 512
 no file open, try 'help open'
 
 == block_size cannot be zero ==
-qemu-io: can't open device TEST_DIR/simple-pattern.cloop: block_size cannot be zero
+can't open device TEST_DIR/simple-pattern.cloop: block_size cannot be zero
 no file open, try 'help open'
 
 == huge block_size ===
-qemu-io: can't open device TEST_DIR/simple-pattern.cloop: block_size 4294966784 must be 64 MB or less
+can't open device TEST_DIR/simple-pattern.cloop: block_size 4294966784 must be 64 MB or less
 no file open, try 'help open'
 
 == offsets_size overflow ===
-qemu-io: can't open device TEST_DIR/simple-pattern.cloop: n_blocks 4294967295 must be 536870911 or less
+can't open device TEST_DIR/simple-pattern.cloop: n_blocks 4294967295 must be 536870911 or less
 no file open, try 'help open'
 
 == refuse images that require too many offsets ===
-qemu-io: can't open device TEST_DIR/simple-pattern.cloop: image requires too many offsets, try increasing block size
+can't open device TEST_DIR/simple-pattern.cloop: image requires too many offsets, try increasing block size
 no file open, try 'help open'
 
 == refuse images with non-monotonically increasing offsets ==
-qemu-io: can't open device TEST_DIR/simple-pattern.cloop: offsets not monotonically increasing at index 1, image file is corrupt
+can't open device TEST_DIR/simple-pattern.cloop: offsets not monotonically increasing at index 1, image file is corrupt
 no file open, try 'help open'
 
 == refuse images with invalid compressed block size ==
-qemu-io: can't open device TEST_DIR/simple-pattern.cloop: invalid compressed block size at index 1, image file is corrupt
+can't open device TEST_DIR/simple-pattern.cloop: invalid compressed block size at index 1, image file is corrupt
 no file open, try 'help open'
 *** done
diff --git a/tests/qemu-iotests/076.out b/tests/qemu-iotests/076.out
index b0000ae..72645b2 100644
--- a/tests/qemu-iotests/076.out
+++ b/tests/qemu-iotests/076.out
@@ -5,15 +5,15 @@
 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 
 == Negative catalog size ==
-qemu-io: can't open device TEST_DIR/parallels-v1: Catalog too large
+can't open device TEST_DIR/parallels-v1: Catalog too large
 no file open, try 'help open'
 
 == Overflow in catalog allocation ==
-qemu-io: can't open device TEST_DIR/parallels-v1: Catalog too large
+can't open device TEST_DIR/parallels-v1: Catalog too large
 no file open, try 'help open'
 
 == Zero sectors per track ==
-qemu-io: can't open device TEST_DIR/parallels-v1: Invalid image: Zero sectors per track
+can't open device TEST_DIR/parallels-v1: Invalid image: Zero sectors per track
 no file open, try 'help open'
 
 == Read from a valid v2 image ==
diff --git a/tests/qemu-iotests/078.out b/tests/qemu-iotests/078.out
index ca18d2e..42b8a83 100644
--- a/tests/qemu-iotests/078.out
+++ b/tests/qemu-iotests/078.out
@@ -5,24 +5,24 @@
 512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 
 == Negative catalog size ==
-qemu-io: can't open device TEST_DIR/empty.bochs: Catalog size is too large
+can't open device TEST_DIR/empty.bochs: Catalog size is too large
 no file open, try 'help open'
 
 == Overflow for catalog size * sizeof(uint32_t) ==
-qemu-io: can't open device TEST_DIR/empty.bochs: Catalog size is too large
+can't open device TEST_DIR/empty.bochs: Catalog size is too large
 no file open, try 'help open'
 
 == Too small catalog bitmap for image size ==
-qemu-io: can't open device TEST_DIR/empty.bochs: Catalog size is too small for this disk size
+can't open device TEST_DIR/empty.bochs: Catalog size is too small for this disk size
 no file open, try 'help open'
-qemu-io: can't open device TEST_DIR/empty.bochs: Catalog size is too small for this disk size
+can't open device TEST_DIR/empty.bochs: Catalog size is too small for this disk size
 no file open, try 'help open'
 
 == Negative extent size ==
-qemu-io: can't open device TEST_DIR/empty.bochs: Extent size 2147483648 is too large
+can't open device TEST_DIR/empty.bochs: Extent size 2147483648 is too large
 no file open, try 'help open'
 
 == Zero extent size ==
-qemu-io: can't open device TEST_DIR/empty.bochs: Extent size must be at least 512
+can't open device TEST_DIR/empty.bochs: Extent size must be at least 512
 no file open, try 'help open'
 *** done
diff --git a/tests/qemu-iotests/080.out b/tests/qemu-iotests/080.out
index 6061d84..0daac48 100644
--- a/tests/qemu-iotests/080.out
+++ b/tests/qemu-iotests/080.out
@@ -2,46 +2,46 @@
 
 == Huge header size ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-qemu-io: can't open device TEST_DIR/t.qcow2: qcow2 header exceeds cluster size
+can't open device TEST_DIR/t.qcow2: qcow2 header exceeds cluster size
 no file open, try 'help open'
-qemu-io: can't open device TEST_DIR/t.qcow2: qcow2 header exceeds cluster size
+can't open device TEST_DIR/t.qcow2: qcow2 header exceeds cluster size
 no file open, try 'help open'
 
 == Huge unknown header extension ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-qemu-io: can't open device TEST_DIR/t.qcow2: Invalid backing file offset
+can't open device TEST_DIR/t.qcow2: Invalid backing file offset
 no file open, try 'help open'
-qemu-io: can't open device TEST_DIR/t.qcow2: Header extension too large
+can't open device TEST_DIR/t.qcow2: Header extension too large
 no file open, try 'help open'
-qemu-io: can't open device TEST_DIR/t.qcow2: Header extension too large
+can't open device TEST_DIR/t.qcow2: Header extension too large
 no file open, try 'help open'
 
 == Huge refcount table size ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-qemu-io: can't open device TEST_DIR/t.qcow2: Reference count table too large
+can't open device TEST_DIR/t.qcow2: Reference count table too large
 no file open, try 'help open'
-qemu-io: can't open device TEST_DIR/t.qcow2: Reference count table too large
+can't open device TEST_DIR/t.qcow2: Reference count table too large
 no file open, try 'help open'
 
 == Misaligned refcount table ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-qemu-io: can't open device TEST_DIR/t.qcow2: Invalid reference count table offset
+can't open device TEST_DIR/t.qcow2: Invalid reference count table offset
 no file open, try 'help open'
 
 == Huge refcount offset ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-qemu-io: can't open device TEST_DIR/t.qcow2: Invalid reference count table offset
+can't open device TEST_DIR/t.qcow2: Invalid reference count table offset
 no file open, try 'help open'
 
 == Invalid snapshot table ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-qemu-io: can't open device TEST_DIR/t.qcow2: Too many snapshots
+can't open device TEST_DIR/t.qcow2: Too many snapshots
 no file open, try 'help open'
-qemu-io: can't open device TEST_DIR/t.qcow2: Too many snapshots
+can't open device TEST_DIR/t.qcow2: Too many snapshots
 no file open, try 'help open'
-qemu-io: can't open device TEST_DIR/t.qcow2: Invalid snapshot table offset
+can't open device TEST_DIR/t.qcow2: Invalid snapshot table offset
 no file open, try 'help open'
-qemu-io: can't open device TEST_DIR/t.qcow2: Invalid snapshot table offset
+can't open device TEST_DIR/t.qcow2: Invalid snapshot table offset
 no file open, try 'help open'
 
 == Hitting snapshot table size limit ==
@@ -52,13 +52,13 @@
 
 == Invalid L1 table ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-qemu-io: can't open device TEST_DIR/t.qcow2: Active L1 table too large
+can't open device TEST_DIR/t.qcow2: Active L1 table too large
 no file open, try 'help open'
-qemu-io: can't open device TEST_DIR/t.qcow2: Active L1 table too large
+can't open device TEST_DIR/t.qcow2: Active L1 table too large
 no file open, try 'help open'
-qemu-io: can't open device TEST_DIR/t.qcow2: Invalid L1 table offset
+can't open device TEST_DIR/t.qcow2: Invalid L1 table offset
 no file open, try 'help open'
-qemu-io: can't open device TEST_DIR/t.qcow2: Invalid L1 table offset
+can't open device TEST_DIR/t.qcow2: Invalid L1 table offset
 no file open, try 'help open'
 
 == Invalid L1 table (with internal snapshot in the image) ==
@@ -67,7 +67,7 @@
 
 == Invalid backing file size ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-qemu-io: can't open device TEST_DIR/t.qcow2: Backing file name too long
+can't open device TEST_DIR/t.qcow2: Backing file name too long
 no file open, try 'help open'
 
 == Invalid L2 entry (huge physical offset) ==
diff --git a/tests/qemu-iotests/083.out b/tests/qemu-iotests/083.out
index 8c1441b..78cc49a 100644
--- a/tests/qemu-iotests/083.out
+++ b/tests/qemu-iotests/083.out
@@ -1,52 +1,52 @@
 QA output created by 083
 === Check disconnect before neg1 ===
 
-qemu-io: can't open device nbd:127.0.0.1:PORT:exportname=foo
+can't open device nbd:127.0.0.1:PORT:exportname=foo
 no file open, try 'help open'
 
 === Check disconnect after neg1 ===
 
-qemu-io: can't open device nbd:127.0.0.1:PORT:exportname=foo
+can't open device nbd:127.0.0.1:PORT:exportname=foo
 no file open, try 'help open'
 
 === Check disconnect 8 neg1 ===
 
-qemu-io: can't open device nbd:127.0.0.1:PORT:exportname=foo
+can't open device nbd:127.0.0.1:PORT:exportname=foo
 no file open, try 'help open'
 
 === Check disconnect 16 neg1 ===
 
-qemu-io: can't open device nbd:127.0.0.1:PORT:exportname=foo
+can't open device nbd:127.0.0.1:PORT:exportname=foo
 no file open, try 'help open'
 
 === Check disconnect before export ===
 
-qemu-io: can't open device nbd:127.0.0.1:PORT:exportname=foo
+can't open device nbd:127.0.0.1:PORT:exportname=foo
 no file open, try 'help open'
 
 === Check disconnect after export ===
 
-qemu-io: can't open device nbd:127.0.0.1:PORT:exportname=foo
+can't open device nbd:127.0.0.1:PORT:exportname=foo
 no file open, try 'help open'
 
 === Check disconnect 4 export ===
 
-qemu-io: can't open device nbd:127.0.0.1:PORT:exportname=foo
+can't open device nbd:127.0.0.1:PORT:exportname=foo
 no file open, try 'help open'
 
 === Check disconnect 12 export ===
 
-qemu-io: can't open device nbd:127.0.0.1:PORT:exportname=foo
+can't open device nbd:127.0.0.1:PORT:exportname=foo
 no file open, try 'help open'
 
 === Check disconnect 16 export ===
 
-qemu-io: can't open device nbd:127.0.0.1:PORT:exportname=foo
+can't open device nbd:127.0.0.1:PORT:exportname=foo
 no file open, try 'help open'
 
 === Check disconnect before neg2 ===
 
-qemu-io: can't open device nbd:127.0.0.1:PORT:exportname=foo
+can't open device nbd:127.0.0.1:PORT:exportname=foo
 no file open, try 'help open'
 
 === Check disconnect after neg2 ===
@@ -56,12 +56,12 @@
 
 === Check disconnect 8 neg2 ===
 
-qemu-io: can't open device nbd:127.0.0.1:PORT:exportname=foo
+can't open device nbd:127.0.0.1:PORT:exportname=foo
 no file open, try 'help open'
 
 === Check disconnect 10 neg2 ===
 
-qemu-io: can't open device nbd:127.0.0.1:PORT:exportname=foo
+can't open device nbd:127.0.0.1:PORT:exportname=foo
 no file open, try 'help open'
 
 === Check disconnect before request ===
@@ -107,27 +107,27 @@
 
 === Check disconnect before neg-classic ===
 
-qemu-io: can't open device nbd:127.0.0.1:PORT
+can't open device nbd:127.0.0.1:PORT
 no file open, try 'help open'
 
 === Check disconnect 8 neg-classic ===
 
-qemu-io: can't open device nbd:127.0.0.1:PORT
+can't open device nbd:127.0.0.1:PORT
 no file open, try 'help open'
 
 === Check disconnect 16 neg-classic ===
 
-qemu-io: can't open device nbd:127.0.0.1:PORT
+can't open device nbd:127.0.0.1:PORT
 no file open, try 'help open'
 
 === Check disconnect 24 neg-classic ===
 
-qemu-io: can't open device nbd:127.0.0.1:PORT
+can't open device nbd:127.0.0.1:PORT
 no file open, try 'help open'
 
 === Check disconnect 28 neg-classic ===
 
-qemu-io: can't open device nbd:127.0.0.1:PORT
+can't open device nbd:127.0.0.1:PORT
 no file open, try 'help open'
 
 === Check disconnect after neg-classic ===
diff --git a/tests/qemu-iotests/088.out b/tests/qemu-iotests/088.out
index 6e6bfca..a2a83b8 100644
--- a/tests/qemu-iotests/088.out
+++ b/tests/qemu-iotests/088.out
@@ -2,16 +2,16 @@
 
 == Invalid block size ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-qemu-io: can't open device TEST_DIR/t.vpc: Invalid block size 0
+can't open device TEST_DIR/t.vpc: Invalid block size 0
 no file open, try 'help open'
-qemu-io: can't open device TEST_DIR/t.vpc: Invalid block size 0
+can't open device TEST_DIR/t.vpc: Invalid block size 0
 no file open, try 'help open'
-qemu-io: can't open device TEST_DIR/t.vpc: Invalid block size 128
+can't open device TEST_DIR/t.vpc: Invalid block size 128
 no file open, try 'help open'
-qemu-io: can't open device TEST_DIR/t.vpc: Invalid block size 128
+can't open device TEST_DIR/t.vpc: Invalid block size 128
 no file open, try 'help open'
-qemu-io: can't open device TEST_DIR/t.vpc: Invalid block size 305419896
+can't open device TEST_DIR/t.vpc: Invalid block size 305419896
 no file open, try 'help open'
-qemu-io: can't open device TEST_DIR/t.vpc: Invalid block size 305419896
+can't open device TEST_DIR/t.vpc: Invalid block size 305419896
 no file open, try 'help open'
 *** done
diff --git a/tests/qemu-iotests/092.out b/tests/qemu-iotests/092.out
index c5c60f9..e18f54c 100644
--- a/tests/qemu-iotests/092.out
+++ b/tests/qemu-iotests/092.out
@@ -2,37 +2,37 @@
 
 == Invalid cluster size ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-qemu-io: can't open device TEST_DIR/t.qcow: Cluster size must be between 512 and 64k
+can't open device TEST_DIR/t.qcow: Cluster size must be between 512 and 64k
 no file open, try 'help open'
-qemu-io: can't open device TEST_DIR/t.qcow: Cluster size must be between 512 and 64k
+can't open device TEST_DIR/t.qcow: Cluster size must be between 512 and 64k
 no file open, try 'help open'
-qemu-io: can't open device TEST_DIR/t.qcow: Cluster size must be between 512 and 64k
+can't open device TEST_DIR/t.qcow: Cluster size must be between 512 and 64k
 no file open, try 'help open'
-qemu-io: can't open device TEST_DIR/t.qcow: Cluster size must be between 512 and 64k
+can't open device TEST_DIR/t.qcow: Cluster size must be between 512 and 64k
 no file open, try 'help open'
 
 == Invalid L2 table size ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-qemu-io: can't open device TEST_DIR/t.qcow: L2 table size must be between 512 and 64k
+can't open device TEST_DIR/t.qcow: L2 table size must be between 512 and 64k
 no file open, try 'help open'
-qemu-io: can't open device TEST_DIR/t.qcow: L2 table size must be between 512 and 64k
+can't open device TEST_DIR/t.qcow: L2 table size must be between 512 and 64k
 no file open, try 'help open'
-qemu-io: can't open device TEST_DIR/t.qcow: L2 table size must be between 512 and 64k
+can't open device TEST_DIR/t.qcow: L2 table size must be between 512 and 64k
 no file open, try 'help open'
-qemu-io: can't open device TEST_DIR/t.qcow: L2 table size must be between 512 and 64k
+can't open device TEST_DIR/t.qcow: L2 table size must be between 512 and 64k
 no file open, try 'help open'
 
 == Invalid size ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-qemu-io: can't open device TEST_DIR/t.qcow: Image too large
+can't open device TEST_DIR/t.qcow: Image too large
 no file open, try 'help open'
-qemu-io: can't open device TEST_DIR/t.qcow: Image too large
+can't open device TEST_DIR/t.qcow: Image too large
 no file open, try 'help open'
 
 == Invalid backing file length ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-qemu-io: can't open device TEST_DIR/t.qcow: Backing file name too long
+can't open device TEST_DIR/t.qcow: Backing file name too long
 no file open, try 'help open'
-qemu-io: can't open device TEST_DIR/t.qcow: Backing file name too long
+can't open device TEST_DIR/t.qcow: Backing file name too long
 no file open, try 'help open'
 *** done
diff --git a/tests/qemu-iotests/103.out b/tests/qemu-iotests/103.out
index d05f49f..b7aaadf 100644
--- a/tests/qemu-iotests/103.out
+++ b/tests/qemu-iotests/103.out
@@ -5,10 +5,10 @@
 
 === Testing invalid option combinations ===
 
-qemu-io: can't open device TEST_DIR/t.IMGFMT: cache-size, l2-cache-size and refcount-cache-size may not be set the same time
-qemu-io: can't open device TEST_DIR/t.IMGFMT: l2-cache-size may not exceed cache-size
-qemu-io: can't open device TEST_DIR/t.IMGFMT: refcount-cache-size may not exceed cache-size
-qemu-io: can't open device TEST_DIR/t.IMGFMT: cache-size, l2-cache-size and refcount-cache-size may not be set the same time
+can't open device TEST_DIR/t.IMGFMT: cache-size, l2-cache-size and refcount-cache-size may not be set the same time
+can't open device TEST_DIR/t.IMGFMT: l2-cache-size may not exceed cache-size
+can't open device TEST_DIR/t.IMGFMT: refcount-cache-size may not exceed cache-size
+can't open device TEST_DIR/t.IMGFMT: cache-size, l2-cache-size and refcount-cache-size may not be set the same time
 
 === Testing valid option combinations ===
 
diff --git a/tests/qemu-iotests/114.out b/tests/qemu-iotests/114.out
index 6a2c750..b6d10e4 100644
--- a/tests/qemu-iotests/114.out
+++ b/tests/qemu-iotests/114.out
@@ -7,7 +7,7 @@
 cluster_size: 65536
 backing file: TEST_DIR/t.IMGFMT.base
 backing file format: foo
-qemu-io: can't open device TEST_DIR/t.qcow2: Could not open backing file: Unknown driver 'foo'
+can't open device TEST_DIR/t.qcow2: Could not open backing file: Unknown driver 'foo'
 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/116.out b/tests/qemu-iotests/116.out
index b679cee..1f11d44 100644
--- a/tests/qemu-iotests/116.out
+++ b/tests/qemu-iotests/116.out
@@ -2,36 +2,36 @@
 
 == truncated header cluster ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728
-qemu-io: can't open device TEST_DIR/t.qed: Could not open 'TEST_DIR/t.qed': Invalid argument
+can't open device TEST_DIR/t.qed: Could not open 'TEST_DIR/t.qed': Invalid argument
 no file open, try 'help open'
 
 == invalid header magic ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728
-qemu-io: can't open device TEST_DIR/t.qed: Image not in QED format
+can't open device TEST_DIR/t.qed: Image not in QED format
 no file open, try 'help open'
 
 == invalid cluster size ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728
-qemu-io: can't open device TEST_DIR/t.qed: Could not open 'TEST_DIR/t.qed': Invalid argument
+can't open device TEST_DIR/t.qed: Could not open 'TEST_DIR/t.qed': Invalid argument
 no file open, try 'help open'
 
 == invalid table size ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728
-qemu-io: can't open device TEST_DIR/t.qed: Could not open 'TEST_DIR/t.qed': Invalid argument
+can't open device TEST_DIR/t.qed: Could not open 'TEST_DIR/t.qed': Invalid argument
 no file open, try 'help open'
 
 == invalid header size ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728
-qemu-io: can't open device TEST_DIR/t.qed: Could not open 'TEST_DIR/t.qed': Invalid argument
+can't open device TEST_DIR/t.qed: Could not open 'TEST_DIR/t.qed': Invalid argument
 no file open, try 'help open'
 
 == invalid L1 table offset ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728
-qemu-io: can't open device TEST_DIR/t.qed: Could not open 'TEST_DIR/t.qed': Invalid argument
+can't open device TEST_DIR/t.qed: Could not open 'TEST_DIR/t.qed': Invalid argument
 no file open, try 'help open'
 
 == invalid image size ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728
-qemu-io: can't open device TEST_DIR/t.qed: Could not open 'TEST_DIR/t.qed': Invalid argument
+can't open device TEST_DIR/t.qed: Could not open 'TEST_DIR/t.qed': Invalid argument
 no file open, try 'help open'
 *** done
diff --git a/tests/qemu-iotests/131.out b/tests/qemu-iotests/131.out
index 021a04c..ae2412e 100644
--- a/tests/qemu-iotests/131.out
+++ b/tests/qemu-iotests/131.out
@@ -22,7 +22,7 @@
 read 32768/32768 bytes at offset 0
 32 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 == Corrupt image ==
-qemu-io: can't open device TEST_DIR/t.parallels: parallels: Image was not closed correctly; cannot be opened read/write
+can't open device TEST_DIR/t.parallels: parallels: Image was not closed correctly; cannot be opened read/write
 no file open, try 'help open'
 ERROR image was not closed correctly