diff --git a/base/services/wkssvc/domain.c b/base/services/wkssvc/domain.c
index 4d39c978fce..69340adfd54 100644
--- a/base/services/wkssvc/domain.c
+++ b/base/services/wkssvc/domain.c
@@ -66,4 +66,63 @@ NetpJoinWorkgroup(
     return NERR_Success;
 }
 
+
+NET_API_STATUS
+NetpGetJoinInformation(
+    LPWSTR *NameBuffer,
+    PNETSETUP_JOIN_STATUS BufferType)
+{
+    LSA_OBJECT_ATTRIBUTES ObjectAttributes;
+    PPOLICY_PRIMARY_DOMAIN_INFO PrimaryDomainInfo = NULL;
+    LSA_HANDLE PolicyHandle = NULL;
+    NTSTATUS Status;
+
+    *BufferType = NetSetupUnknownStatus;
+    *NameBuffer = NULL;
+
+    ZeroMemory(&ObjectAttributes, sizeof(LSA_OBJECT_ATTRIBUTES));
+    ObjectAttributes.Length = sizeof(LSA_OBJECT_ATTRIBUTES);
+
+    Status = LsaOpenPolicy(NULL,
+                           &ObjectAttributes,
+                           POLICY_VIEW_LOCAL_INFORMATION,
+                           &PolicyHandle);
+    if (!LSA_SUCCESS(Status))
+        return LsaNtStatusToWinError(Status);
+
+    Status = LsaQueryInformationPolicy(PolicyHandle,
+                                       PolicyPrimaryDomainInformation,
+                                       (PVOID*)&PrimaryDomainInfo);
+    if (LSA_SUCCESS(Status))
+    {
+        TRACE("Sid: %p\n", PrimaryDomainInfo->Sid);
+        TRACE("Name: %S\n", PrimaryDomainInfo->Name.Buffer);
+
+        if (PrimaryDomainInfo->Name.Length > 0)
+        {
+            if (PrimaryDomainInfo->Sid != NULL)
+                *BufferType = NetSetupDomainName;
+            else
+                *BufferType = NetSetupWorkgroupName;
+
+            *NameBuffer = midl_user_allocate(PrimaryDomainInfo->Name.Length + sizeof(WCHAR));
+            if (*NameBuffer)
+                wcscpy(*NameBuffer, PrimaryDomainInfo->Name.Buffer);
+        }
+        else
+        {
+            *BufferType = NetSetupUnjoined;
+        }
+
+        if (PrimaryDomainInfo->Sid)
+            LsaFreeMemory(PrimaryDomainInfo->Sid);
+
+        LsaFreeMemory(PrimaryDomainInfo);
+    }
+
+    LsaClose(PolicyHandle);
+
+    return LsaNtStatusToWinError(Status);
+}
+
 /* EOF */
diff --git a/base/services/wkssvc/precomp.h b/base/services/wkssvc/precomp.h
index c6f841e1eb4..be3c7982465 100644
--- a/base/services/wkssvc/precomp.h
+++ b/base/services/wkssvc/precomp.h
@@ -28,6 +28,11 @@ NET_API_STATUS
 NetpJoinWorkgroup(
     _In_ LPCWSTR WorkgroupName);
 
+NET_API_STATUS
+NetpGetJoinInformation(
+    LPWSTR *NameBuffer,
+    PNETSETUP_JOIN_STATUS BufferType);
+
 
 /* rpcserver.c */
 
diff --git a/base/services/wkssvc/rpcserver.c b/base/services/wkssvc/rpcserver.c
index 47f96f8921a..79a062c8ecc 100644
--- a/base/services/wkssvc/rpcserver.c
+++ b/base/services/wkssvc/rpcserver.c
@@ -364,12 +364,14 @@ NetrGetJoinInformation(
     wchar_t **NameBuffer,
     PNETSETUP_JOIN_STATUS BufferType)
 {
-    TRACE("NetrGetJoinInformation()\n");
+    TRACE("NetrGetJoinInformation(%p %p %p)\n",
+          ServerName, NameBuffer, BufferType);
 
-    *NameBuffer = NULL;
-    *BufferType = NetSetupUnjoined;
+    if (NameBuffer == NULL)
+        return ERROR_INVALID_PARAMETER;
 
-    return NERR_Success;
+    return NetpGetJoinInformation(NameBuffer,
+                                  BufferType);
 }
 
 
diff --git a/dll/win32/netapi32/wksta.c b/dll/win32/netapi32/wksta.c
index 616833c98c1..9200b17aaa0 100644
--- a/dll/win32/netapi32/wksta.c
+++ b/dll/win32/netapi32/wksta.c
@@ -552,22 +552,3 @@ NET_API_STATUS WINAPI NetWkstaGetInfo( LMSTR servername, DWORD level,
     }
     return ret;
 }
-
-/************************************************************
- *                NetGetJoinInformation (NETAPI32.@)
- */
-NET_API_STATUS NET_API_FUNCTION NetGetJoinInformation(
-    LPCWSTR Server,
-    LPWSTR *Name,
-    PNETSETUP_JOIN_STATUS type)
-{
-    FIXME("Stub %s %p %p\n", wine_dbgstr_w(Server), Name, type);
-
-    if (Name == NULL || type == NULL)
-        return ERROR_INVALID_PARAMETER;
-
-    *Name = NULL;
-    *type = NetSetupUnknownStatus;
-
-    return NERR_Success;
-}
diff --git a/dll/win32/netapi32/wksta_new.c b/dll/win32/netapi32/wksta_new.c
index a8eb1da2c84..1853b2052a7 100644
--- a/dll/win32/netapi32/wksta_new.c
+++ b/dll/win32/netapi32/wksta_new.c
@@ -312,7 +312,6 @@ NetEnumerateComputerNames(
 }
 
 
-#if 0
 NET_API_STATUS
 WINAPI
 NetGetJoinInformation(
@@ -342,7 +341,6 @@ NetGetJoinInformation(
 
     return status;
 }
-#endif
 
 
 NET_API_STATUS
@@ -594,7 +592,7 @@ NetSetPrimaryComputerName(
 NET_API_STATUS
 WINAPI
 NetUnjoinDomain(
-    _In_ LPCWSTR lpServer,
+    _In_opt_ LPCWSTR lpServer,
     _In_opt_ LPCWSTR lpAccount,
     _In_opt_ LPCWSTR lpPassword,
     _In_ DWORD fUnjoinOptions)