diff --git a/src/vmx/vmx.c b/src/vmx/vmx.c
index 40416a0f88..5c2c79430f 100644
--- a/src/vmx/vmx.c
+++ b/src/vmx/vmx.c
@@ -2221,14 +2221,26 @@ virVMXParseDisk(virVMXContext *ctx, virDomainXMLOptionPtr xmlopt, virConfPtr con
             goto ignore;
         } else if (STRCASEEQ(deviceType, "atapi-cdrom")) {
             (*def)->type = VIR_DOMAIN_DISK_TYPE_BLOCK;
-            (*def)->src = fileName;
-            fileName = NULL;
+
+            if (STRCASEEQ(fileName, "auto detect")) {
+                (*def)->src = NULL;
+                (*def)->startupPolicy = VIR_DOMAIN_STARTUP_POLICY_OPTIONAL;
+            } else {
+                (*def)->src = fileName;
+                fileName = NULL;
+            }
         } else if (STRCASEEQ(deviceType, "cdrom-raw")) {
             /* Raw access CD-ROMs actually are device='lun' */
             (*def)->device = VIR_DOMAIN_DISK_DEVICE_LUN;
             (*def)->type = VIR_DOMAIN_DISK_TYPE_BLOCK;
-            (*def)->src = fileName;
-            fileName = NULL;
+
+            if (STRCASEEQ(fileName, "auto detect")) {
+                (*def)->src = NULL;
+                (*def)->startupPolicy = VIR_DOMAIN_STARTUP_POLICY_OPTIONAL;
+            } else {
+                (*def)->src = fileName;
+                fileName = NULL;
+            }
         } else {
             virReportError(VIR_ERR_INTERNAL_ERROR,
                            _("Invalid or not yet handled value '%s' "
@@ -3473,7 +3485,13 @@ virVMXFormatDisk(virVMXContext *ctx, virDomainDiskDefPtr def,
 
         VIR_FREE(fileName);
     } else if (def->type == VIR_DOMAIN_DISK_TYPE_BLOCK) {
-        if (def->src != NULL) {
+        if (!def->src &&
+            def->startupPolicy == VIR_DOMAIN_STARTUP_POLICY_OPTIONAL) {
+            virBufferAsprintf(buffer, "%s%d:%d.autodetect = \"true\"\n",
+                              busType, controllerOrBus, unit);
+            virBufferAsprintf(buffer, "%s%d:%d.fileName = \"auto detect\"\n",
+                              busType, controllerOrBus, unit);
+        } else {
             virBufferAsprintf(buffer, "%s%d:%d.fileName = \"%s\"\n",
                               busType, controllerOrBus, unit, def->src);
         }
diff --git a/tests/vmx2xmldata/vmx2xml-cdrom-ide-raw-auto-detect.vmx b/tests/vmx2xmldata/vmx2xml-cdrom-ide-raw-auto-detect.vmx
new file mode 100644
index 0000000000..b2c4caf20f
--- /dev/null
+++ b/tests/vmx2xmldata/vmx2xml-cdrom-ide-raw-auto-detect.vmx
@@ -0,0 +1,5 @@
+config.version = "8"
+virtualHW.version = "4"
+ide0:0.present = "true"
+ide0:0.deviceType = "cdrom-raw"
+ide0:0.fileName = "auto detect"
diff --git a/tests/vmx2xmldata/vmx2xml-cdrom-ide-raw-auto-detect.xml b/tests/vmx2xmldata/vmx2xml-cdrom-ide-raw-auto-detect.xml
new file mode 100644
index 0000000000..bce708d1f7
--- /dev/null
+++ b/tests/vmx2xmldata/vmx2xml-cdrom-ide-raw-auto-detect.xml
@@ -0,0 +1,24 @@
+<domain type='vmware'>
+  <uuid>00000000-0000-0000-0000-000000000000</uuid>
+  <memory unit='KiB'>32768</memory>
+  <currentMemory unit='KiB'>32768</currentMemory>
+  <vcpu placement='static'>1</vcpu>
+  <os>
+    <type arch='i686'>hvm</type>
+  </os>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+    <disk type='block' device='lun'>
+      <source startupPolicy='optional'/>
+      <target dev='hda' bus='ide'/>
+      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
+    </disk>
+    <controller type='ide' index='0'/>
+    <video>
+      <model type='vmvga' vram='4096'/>
+    </video>
+  </devices>
+</domain>
diff --git a/tests/vmx2xmldata/vmx2xml-cdrom-scsi-raw-auto-detect.vmx b/tests/vmx2xmldata/vmx2xml-cdrom-scsi-raw-auto-detect.vmx
new file mode 100644
index 0000000000..0209b291e6
--- /dev/null
+++ b/tests/vmx2xmldata/vmx2xml-cdrom-scsi-raw-auto-detect.vmx
@@ -0,0 +1,6 @@
+config.version = "8"
+virtualHW.version = "4"
+scsi0.present = "true"
+scsi0:0.present = "true"
+scsi0:0.deviceType = "cdrom-raw"
+scsi0:0.fileName = "auto detect"
diff --git a/tests/vmx2xmldata/vmx2xml-cdrom-scsi-raw-auto-detect.xml b/tests/vmx2xmldata/vmx2xml-cdrom-scsi-raw-auto-detect.xml
new file mode 100644
index 0000000000..a81646a28e
--- /dev/null
+++ b/tests/vmx2xmldata/vmx2xml-cdrom-scsi-raw-auto-detect.xml
@@ -0,0 +1,24 @@
+<domain type='vmware'>
+  <uuid>00000000-0000-0000-0000-000000000000</uuid>
+  <memory unit='KiB'>32768</memory>
+  <currentMemory unit='KiB'>32768</currentMemory>
+  <vcpu placement='static'>1</vcpu>
+  <os>
+    <type arch='i686'>hvm</type>
+  </os>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+    <disk type='block' device='lun'>
+      <source startupPolicy='optional'/>
+      <target dev='sda' bus='scsi'/>
+      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
+    </disk>
+    <controller type='scsi' index='0'/>
+    <video>
+      <model type='vmvga' vram='4096'/>
+    </video>
+  </devices>
+</domain>
diff --git a/tests/vmx2xmltest.c b/tests/vmx2xmltest.c
index 479c84c14c..5eb04e9ea4 100644
--- a/tests/vmx2xmltest.c
+++ b/tests/vmx2xmltest.c
@@ -238,9 +238,11 @@ mymain(void)
     DO_TEST("cdrom-scsi-file", "cdrom-scsi-file");
     DO_TEST("cdrom-scsi-device", "cdrom-scsi-device");
     DO_TEST("cdrom-scsi-raw-device", "cdrom-scsi-raw-device");
+    DO_TEST("cdrom-scsi-raw-auto-detect", "cdrom-scsi-raw-auto-detect");
     DO_TEST("cdrom-ide-file", "cdrom-ide-file");
     DO_TEST("cdrom-ide-device", "cdrom-ide-device");
     DO_TEST("cdrom-ide-raw-device", "cdrom-ide-raw-device");
+    DO_TEST("cdrom-ide-raw-auto-detect", "cdrom-ide-raw-auto-detect");
 
     DO_TEST("floppy-file", "floppy-file");
     DO_TEST("floppy-device", "floppy-device");
diff --git a/tests/xml2vmxdata/xml2vmx-cdrom-ide-raw-auto-detect.vmx b/tests/xml2vmxdata/xml2vmx-cdrom-ide-raw-auto-detect.vmx
new file mode 100644
index 0000000000..34e1467e1f
--- /dev/null
+++ b/tests/xml2vmxdata/xml2vmx-cdrom-ide-raw-auto-detect.vmx
@@ -0,0 +1,14 @@
+.encoding = "UTF-8"
+config.version = "8"
+virtualHW.version = "4"
+guestOS = "other"
+uuid.bios = "56 4d 9b ef ac d9 b4 e0-c8 f0 ae a8 b9 10 35 15"
+displayName = "cdrom-ide-device"
+memsize = "4"
+numvcpus = "1"
+ide0:0.present = "true"
+ide0:0.deviceType = "cdrom-raw"
+ide0:0.autodetect = "true"
+ide0:0.fileName = "auto detect"
+floppy0.present = "false"
+floppy1.present = "false"
diff --git a/tests/xml2vmxdata/xml2vmx-cdrom-ide-raw-auto-detect.xml b/tests/xml2vmxdata/xml2vmx-cdrom-ide-raw-auto-detect.xml
new file mode 100644
index 0000000000..166410c09e
--- /dev/null
+++ b/tests/xml2vmxdata/xml2vmx-cdrom-ide-raw-auto-detect.xml
@@ -0,0 +1,14 @@
+<domain type='vmware'>
+  <name>cdrom-ide-device</name>
+  <uuid>564d9bef-acd9-b4e0-c8f0-aea8b9103515</uuid>
+  <memory unit='KiB'>4096</memory>
+  <os>
+    <type>hvm</type>
+  </os>
+  <devices>
+    <disk type='block' device='lun'>
+      <source startupPolicy='optional'/>
+      <target dev='hda' bus='ide'/>
+    </disk>
+  </devices>
+</domain>
diff --git a/tests/xml2vmxdata/xml2vmx-cdrom-scsi-raw-auto-detect.vmx b/tests/xml2vmxdata/xml2vmx-cdrom-scsi-raw-auto-detect.vmx
new file mode 100644
index 0000000000..84ec646cef
--- /dev/null
+++ b/tests/xml2vmxdata/xml2vmx-cdrom-scsi-raw-auto-detect.vmx
@@ -0,0 +1,15 @@
+.encoding = "UTF-8"
+config.version = "8"
+virtualHW.version = "4"
+guestOS = "other"
+uuid.bios = "56 4d 9b ef ac d9 b4 e0-c8 f0 ae a8 b9 10 35 15"
+displayName = "cdrom-scsi-device"
+memsize = "4"
+numvcpus = "1"
+scsi0.present = "true"
+scsi0:0.present = "true"
+scsi0:0.deviceType = "cdrom-raw"
+scsi0:0.autodetect = "true"
+scsi0:0.fileName = "auto detect"
+floppy0.present = "false"
+floppy1.present = "false"
diff --git a/tests/xml2vmxdata/xml2vmx-cdrom-scsi-raw-auto-detect.xml b/tests/xml2vmxdata/xml2vmx-cdrom-scsi-raw-auto-detect.xml
new file mode 100644
index 0000000000..6531ec8ba1
--- /dev/null
+++ b/tests/xml2vmxdata/xml2vmx-cdrom-scsi-raw-auto-detect.xml
@@ -0,0 +1,14 @@
+<domain type='vmware'>
+  <name>cdrom-scsi-device</name>
+  <uuid>564d9bef-acd9-b4e0-c8f0-aea8b9103515</uuid>
+  <memory unit='KiB'>4096</memory>
+  <os>
+    <type>hvm</type>
+  </os>
+  <devices>
+    <disk type='block' device='lun'>
+      <source startupPolicy='optional'/>
+      <target dev='sda' bus='scsi'/>
+    </disk>
+  </devices>
+</domain>
diff --git a/tests/xml2vmxtest.c b/tests/xml2vmxtest.c
index cb1c29c46d..cafcc368ff 100644
--- a/tests/xml2vmxtest.c
+++ b/tests/xml2vmxtest.c
@@ -254,9 +254,11 @@ mymain(void)
     DO_TEST("cdrom-scsi-file", "cdrom-scsi-file", 4);
     DO_TEST("cdrom-scsi-device", "cdrom-scsi-device", 4);
     DO_TEST("cdrom-scsi-raw-device", "cdrom-scsi-raw-device", 4);
+    DO_TEST("cdrom-scsi-raw-auto-detect", "cdrom-scsi-raw-auto-detect", 4);
     DO_TEST("cdrom-ide-file", "cdrom-ide-file", 4);
     DO_TEST("cdrom-ide-device", "cdrom-ide-device", 4);
     DO_TEST("cdrom-ide-raw-device", "cdrom-ide-raw-device", 4);
+    DO_TEST("cdrom-ide-raw-auto-detect", "cdrom-ide-raw-auto-detect", 4);
 
     DO_TEST("floppy-file", "floppy-file", 4);
     DO_TEST("floppy-device", "floppy-device", 4);