diff --git a/src/esx/esx_driver.c b/src/esx/esx_driver.c
index 08d33b6f3b..d80fef0a58 100644
--- a/src/esx/esx_driver.c
+++ b/src/esx/esx_driver.c
@@ -2710,7 +2710,7 @@ esxConnectDomainXMLFromNative(virConnectPtr conn, const char *nativeFormat,
 
     memset(&data, 0, sizeof(data));
 
-    if (STRNEQ(nativeFormat, "vmware-vmx")) {
+    if (STRNEQ(nativeFormat, VMX_CONFIG_FORMAT_ARGV)) {
         virReportError(VIR_ERR_INVALID_ARG,
                        _("Unsupported config format '%s'"), nativeFormat);
         return NULL;
@@ -2755,7 +2755,7 @@ esxConnectDomainXMLToNative(virConnectPtr conn, const char *nativeFormat,
 
     memset(&data, 0, sizeof(data));
 
-    if (STRNEQ(nativeFormat, "vmware-vmx")) {
+    if (STRNEQ(nativeFormat, VMX_CONFIG_FORMAT_ARGV)) {
         virReportError(VIR_ERR_INVALID_ARG,
                        _("Unsupported config format '%s'"), nativeFormat);
         return NULL;
diff --git a/src/vmware/vmware_driver.c b/src/vmware/vmware_driver.c
index f4b0989afd..1bc8a06c39 100644
--- a/src/vmware/vmware_driver.c
+++ b/src/vmware/vmware_driver.c
@@ -956,7 +956,7 @@ vmwareConnectDomainXMLFromNative(virConnectPtr conn, const char *nativeFormat,
 
     virCheckFlags(0, NULL);
 
-    if (STRNEQ(nativeFormat, "vmware-vmx")) {
+    if (STRNEQ(nativeFormat, VMX_CONFIG_FORMAT_ARGV)) {
         virReportError(VIR_ERR_INVALID_ARG,
                        _("Unsupported config format '%s'"), nativeFormat);
         return NULL;
diff --git a/src/vmx/vmx.h b/src/vmx/vmx.h
index cb99e84d18..8c068b4cb2 100644
--- a/src/vmx/vmx.h
+++ b/src/vmx/vmx.h
@@ -26,6 +26,8 @@
 # include "virconf.h"
 # include "domain_conf.h"
 
+# define VMX_CONFIG_FORMAT_ARGV "vmware-vmx"
+
 typedef struct _virVMXContext virVMXContext;
 
 virDomainXMLOptionPtr virVMXDomainXMLConfInit(void);