diff --git a/docs/drvesx.html.in b/docs/drvesx.html.in
index 7d323b3521..11df124d3b 100644
--- a/docs/drvesx.html.in
+++ b/docs/drvesx.html.in
@@ -2,10 +2,10 @@
     <h1>VMware ESX hypervisor driver</h1>
     <ul id="toc"></ul>
     <p>
-        The libvirt VMware ESX driver can manage VMware ESX/ESXi 3.5/4.x and
+        The libvirt VMware ESX driver can manage VMware ESX/ESXi 3.5/4.x/5.x and
         VMware GSX 2.0, also called VMware Server 2.0, and possibly later
         versions. <span class="since">Since 0.8.3</span> the driver can also
-        connect to a VMware vCenter 2.5/4.x (VPX).
+        connect to a VMware vCenter 2.5/4.x/5.x (VPX).
     </p>
 
     <h2><a name="project">Project Links</a></h2>
diff --git a/src/esx/esx_vi.c b/src/esx/esx_vi.c
index 125eaee438..0d2b970226 100644
--- a/src/esx/esx_vi.c
+++ b/src/esx/esx_vi.c
@@ -833,16 +833,12 @@ esxVI_Context_Connect(esxVI_Context *ctx, const char *url,
             ctx->apiVersion = esxVI_APIVersion_41;
         } else if (STRPREFIX(ctx->service->about->apiVersion, "4.")) {
             ctx->apiVersion = esxVI_APIVersion_4x;
-
-            VIR_WARN("Found untested VI API major/minor version '%s'",
-                     ctx->service->about->apiVersion);
         } else if (STRPREFIX(ctx->service->about->apiVersion, "5.0")) {
             ctx->apiVersion = esxVI_APIVersion_50;
+        } else if (STRPREFIX(ctx->service->about->apiVersion, "5.1")) {
+            ctx->apiVersion = esxVI_APIVersion_51;
         } else if (STRPREFIX(ctx->service->about->apiVersion, "5.")) {
             ctx->apiVersion = esxVI_APIVersion_5x;
-
-            VIR_WARN("Found untested VI API major/minor version '%s'",
-                     ctx->service->about->apiVersion);
         } else {
             virReportError(VIR_ERR_INTERNAL_ERROR,
                            _("Expecting VI API major/minor version '2.5', '4.x' or "
@@ -869,16 +865,12 @@ esxVI_Context_Connect(esxVI_Context *ctx, const char *url,
                 ctx->productVersion = esxVI_ProductVersion_ESX41;
             } else if (STRPREFIX(ctx->service->about->version, "4.")) {
                 ctx->productVersion = esxVI_ProductVersion_ESX4x;
-
-                VIR_WARN("Found untested ESX major/minor version '%s'",
-                         ctx->service->about->version);
             } else if (STRPREFIX(ctx->service->about->version, "5.0")) {
                 ctx->productVersion = esxVI_ProductVersion_ESX50;
+            } else if (STRPREFIX(ctx->service->about->version, "5.1")) {
+                ctx->productVersion = esxVI_ProductVersion_ESX51;
             } else if (STRPREFIX(ctx->service->about->version, "5.")) {
                 ctx->productVersion = esxVI_ProductVersion_ESX5x;
-
-                VIR_WARN("Found untested ESX major/minor version '%s'",
-                         ctx->service->about->version);
             } else {
                 virReportError(VIR_ERR_INTERNAL_ERROR,
                                _("Expecting ESX major/minor version '3.5', "
@@ -895,16 +887,12 @@ esxVI_Context_Connect(esxVI_Context *ctx, const char *url,
                 ctx->productVersion = esxVI_ProductVersion_VPX41;
             } else if (STRPREFIX(ctx->service->about->version, "4.")) {
                 ctx->productVersion = esxVI_ProductVersion_VPX4x;
-
-                VIR_WARN("Found untested VPX major/minor version '%s'",
-                         ctx->service->about->version);
             } else if (STRPREFIX(ctx->service->about->version, "5.0")) {
                 ctx->productVersion = esxVI_ProductVersion_VPX50;
+            } else if (STRPREFIX(ctx->service->about->version, "5.1")) {
+                ctx->productVersion = esxVI_ProductVersion_VPX51;
             } else if (STRPREFIX(ctx->service->about->version, "5.")) {
                 ctx->productVersion = esxVI_ProductVersion_VPX5x;
-
-                VIR_WARN("Found untested VPX major/minor version '%s'",
-                         ctx->service->about->version);
             } else {
                 virReportError(VIR_ERR_INTERNAL_ERROR,
                                _("Expecting VPX major/minor version '2.5', '4.x' "
diff --git a/src/esx/esx_vi.h b/src/esx/esx_vi.h
index 3471fea4ea..a9c12c8a00 100644
--- a/src/esx/esx_vi.h
+++ b/src/esx/esx_vi.h
@@ -95,7 +95,8 @@ enum _esxVI_APIVersion {
     esxVI_APIVersion_41,
     esxVI_APIVersion_4x, /* > 4.1 */
     esxVI_APIVersion_50,
-    esxVI_APIVersion_5x  /* > 5.0 */
+    esxVI_APIVersion_51,
+    esxVI_APIVersion_5x  /* > 5.1 */
 };
 
 /*
@@ -114,7 +115,8 @@ enum _esxVI_ProductVersion {
     esxVI_ProductVersion_ESX41 = esxVI_ProductVersion_ESX | 3,
     esxVI_ProductVersion_ESX4x = esxVI_ProductVersion_ESX | 4, /* > 4.1 */
     esxVI_ProductVersion_ESX50 = esxVI_ProductVersion_ESX | 5,
-    esxVI_ProductVersion_ESX5x = esxVI_ProductVersion_ESX | 6, /* > 5.0 */
+    esxVI_ProductVersion_ESX51 = esxVI_ProductVersion_ESX | 6,
+    esxVI_ProductVersion_ESX5x = esxVI_ProductVersion_ESX | 7, /* > 5.1 */
 
     esxVI_ProductVersion_VPX   = (1 << 2) << 16,
     esxVI_ProductVersion_VPX25 = esxVI_ProductVersion_VPX | 1,
@@ -122,7 +124,8 @@ enum _esxVI_ProductVersion {
     esxVI_ProductVersion_VPX41 = esxVI_ProductVersion_VPX | 3,
     esxVI_ProductVersion_VPX4x = esxVI_ProductVersion_VPX | 4, /* > 4.1 */
     esxVI_ProductVersion_VPX50 = esxVI_ProductVersion_VPX | 5,
-    esxVI_ProductVersion_VPX5x = esxVI_ProductVersion_VPX | 6  /* > 5.0 */
+    esxVI_ProductVersion_VPX51 = esxVI_ProductVersion_VPX | 6,
+    esxVI_ProductVersion_VPX5x = esxVI_ProductVersion_VPX | 7  /* > 5.1 */
 };
 
 enum _esxVI_Occurrence {