diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index cd097527f46351cf4de66008222500c9992f0d4c..68c1e28ec40e54591ce483eb4aef1dd6b590d7d5 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -4124,6 +4124,13 @@ qemuDomainValidateStorageSource(virStorageSourcePtr src)
         return -1;
     }
 
+    if (src->format == VIR_STORAGE_FILE_ISO) {
+        virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                       _("storage format 'iso' is not directly supported by QEMU, "
+                         "use 'raw' instead"));
+        return -1;
+    }
+
     return 0;
 }
 
diff --git a/tests/qemuxml2argvdata/disk-drive-fmt-iso.xml b/tests/qemuxml2argvdata/disk-drive-fmt-iso.xml
new file mode 100644
index 0000000000000000000000000000000000000000..ad2825bfb2527b888cbac51fdbf1c02284d01cc1
--- /dev/null
+++ b/tests/qemuxml2argvdata/disk-drive-fmt-iso.xml
@@ -0,0 +1,27 @@
+<domain type='qemu'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <memory unit='KiB'>219136</memory>
+  <currentMemory unit='KiB'>219136</currentMemory>
+  <vcpu placement='static'>1</vcpu>
+  <os>
+    <type arch='i686' machine='pc'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <clock offset='utc'/>
+  <devices>
+    <emulator>/usr/bin/qemu-system-i686</emulator>
+    <disk type='file' device='disk'>
+      <driver name='qemu' type='iso'/>
+      <source file='/dev/HostVG/QEMUGuest1'/>
+      <target dev='hda' bus='ide'/>
+      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
+    </disk>
+    <controller type='usb' index='0'/>
+    <controller type='ide' index='0'/>
+    <controller type='pci' index='0' model='pci-root'/>
+    <input type='mouse' bus='ps2'/>
+    <input type='keyboard' bus='ps2'/>
+    <memballoon model='none'/>
+  </devices>
+</domain>
diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c
index 711bd1b6616d62896cdd553102b3d03abe1386aa..3d278c4bc269e78c601393d6d5411c798a5a7bac 100644
--- a/tests/qemuxml2argvtest.c
+++ b/tests/qemuxml2argvtest.c
@@ -914,6 +914,7 @@ mymain(void)
             QEMU_CAPS_DRIVE_BOOT);
     DO_TEST_PARSE_ERROR("disk-drive-fmt-cow", QEMU_CAPS_DRIVE_BOOT);
     DO_TEST_PARSE_ERROR("disk-drive-fmt-dir", QEMU_CAPS_DRIVE_BOOT);
+    DO_TEST_PARSE_ERROR("disk-drive-fmt-iso", QEMU_CAPS_DRIVE_BOOT);
     DO_TEST("disk-drive-shared",
             QEMU_CAPS_DRIVE_SERIAL);
     DO_TEST_PARSE_ERROR("disk-drive-shared-qcow", NONE);