diff --git a/dlls/rpcrt4/rpc_binding.c b/dlls/rpcrt4/rpc_binding.c
index b29ab1363c1..333de3d14cf 100644
--- a/dlls/rpcrt4/rpc_binding.c
+++ b/dlls/rpcrt4/rpc_binding.c
@@ -1404,7 +1404,8 @@ RpcBindingSetAuthInfoExA( RPC_BINDING_HANDLE Binding, RPC_CSTR ServerPrincName,
     return RPC_S_UNKNOWN_AUTHN_LEVEL;
   }
 
-  if (AuthzSvr)
+  /* RPC_C_AUTHN_WINNT ignores the AuthzSvr parameter */
+  if (AuthzSvr && AuthnSvc != RPC_C_AUTHN_WINNT)
   {
     FIXME("unsupported AuthzSvr %u\n", AuthzSvr);
     return RPC_S_UNKNOWN_AUTHZ_SERVICE;
@@ -1533,7 +1534,8 @@ RpcBindingSetAuthInfoExW( RPC_BINDING_HANDLE Binding, RPC_WSTR ServerPrincName,
     return RPC_S_UNKNOWN_AUTHN_LEVEL;
   }
 
-  if (AuthzSvr)
+  /* RPC_C_AUTHN_WINNT ignores the AuthzSvr parameter */
+  if (AuthzSvr && AuthnSvc != RPC_C_AUTHN_WINNT)
   {
     FIXME("unsupported AuthzSvr %u\n", AuthzSvr);
     return RPC_S_UNKNOWN_AUTHZ_SERVICE;
diff --git a/dlls/rpcrt4/tests/rpc.c b/dlls/rpcrt4/tests/rpc.c
index 035cde7bd89..4b34d121c40 100644
--- a/dlls/rpcrt4/tests/rpc.c
+++ b/dlls/rpcrt4/tests/rpc.c
@@ -260,6 +260,10 @@ todo_wine {
     ok(status == RPC_S_OK, "RpcBindingFromStringBinding failed (%lu)\n",
        status);
 
+    status = RpcBindingSetAuthInfo(IFoo_IfHandle, NULL, RPC_C_AUTHN_LEVEL_NONE,
+                                   RPC_C_AUTHN_WINNT, NULL, RPC_C_AUTHZ_NAME);
+    ok(status == RPC_S_OK, "RpcBindingSetAuthInfo failed (%lu)\n", status);
+
     status = RpcMgmtStopServerListening(NULL);
     ok(status == RPC_S_OK, "RpcMgmtStopServerListening failed (%lu)\n",
        status);
diff --git a/include/rpcdce.h b/include/rpcdce.h
index 0212c4c3735..6bc656121d0 100644
--- a/include/rpcdce.h
+++ b/include/rpcdce.h
@@ -139,6 +139,11 @@ typedef I_RPC_HANDLE *RPC_EP_INQ_HANDLE;
 #define RPC_C_AUTHN_MQ 100
 #define RPC_C_AUTHN_DEFAULT 0xffffffff
 
+#define RPC_C_AUTHZ_NONE 0
+#define RPC_C_AUTHZ_NAME 1
+#define RPC_C_AUTHZ_DCE  2
+#define RPC_C_AUTHZ_DEFAULT 0xffffffff
+
 /* values for RPC_SECURITY_QOS*::ImpersonationType */
 #define RPC_C_IMP_LEVEL_DEFAULT     0
 #define RPC_C_IMP_LEVEL_ANONYMOUS   1