diff --git a/dlls/rpcrt4/tests/server.c b/dlls/rpcrt4/tests/server.c
index 353d0cd..28a426b 100644
--- a/dlls/rpcrt4/tests/server.c
+++ b/dlls/rpcrt4/tests/server.c
@@ -1429,7 +1429,8 @@ client(const char *test)
     ok(RPC_S_OK == RpcBindingFromStringBinding(binding, &IServer_IfHandle), "RpcBindingFromStringBinding\n");
 
     run_tests();
-    authinfo_test(RPC_PROTSEQ_TCP, 0);
+    if (pGetUserNameExA)
+      authinfo_test(RPC_PROTSEQ_TCP, 0);
 
     ok(RPC_S_OK == RpcStringFree(&binding), "RpcStringFree\n");
     ok(RPC_S_OK == RpcBindingFree(&IServer_IfHandle), "RpcBindingFree\n");
@@ -1439,8 +1440,11 @@ client(const char *test)
     ok(RPC_S_OK == RpcStringBindingCompose(NULL, iptcp, address, port, NULL, &binding), "RpcStringBindingCompose\n");
     ok(RPC_S_OK == RpcBindingFromStringBinding(binding, &IServer_IfHandle), "RpcBindingFromStringBinding\n");
 
-    set_auth_info(IServer_IfHandle);
-    authinfo_test(RPC_PROTSEQ_TCP, 1);
+    if (pGetUserNameExA)
+    {
+      set_auth_info(IServer_IfHandle);
+      authinfo_test(RPC_PROTSEQ_TCP, 1);
+    }
 
     ok(RPC_S_OK == RpcStringFree(&binding), "RpcStringFree\n");
     ok(RPC_S_OK == RpcBindingFree(&IServer_IfHandle), "RpcBindingFree\n");
@@ -1451,7 +1455,8 @@ client(const char *test)
     ok(RPC_S_OK == RpcBindingFromStringBinding(binding, &IServer_IfHandle), "RpcBindingFromStringBinding\n");
 
     run_tests(); /* can cause RPC_X_BAD_STUB_DATA exception */
-    authinfo_test(RPC_PROTSEQ_LRPC, 0);
+    if (pGetUserNameExA)
+      authinfo_test(RPC_PROTSEQ_LRPC, 0);
 
     ok(RPC_S_OK == RpcStringFree(&binding), "RpcStringFree\n");
     ok(RPC_S_OK == RpcBindingFree(&IServer_IfHandle), "RpcBindingFree\n");
@@ -1461,8 +1466,11 @@ client(const char *test)
     ok(RPC_S_OK == RpcStringBindingCompose(NULL, ncalrpc, NULL, guid, NULL, &binding), "RpcStringBindingCompose\n");
     ok(RPC_S_OK == RpcBindingFromStringBinding(binding, &IServer_IfHandle), "RpcBindingFromStringBinding\n");
 
-    set_auth_info(IServer_IfHandle);
-    authinfo_test(RPC_PROTSEQ_LRPC, 1);
+    if (pGetUserNameExA)
+    {
+      set_auth_info(IServer_IfHandle);
+      authinfo_test(RPC_PROTSEQ_LRPC, 1);
+    }
 
     ok(RPC_S_OK == RpcStringFree(&binding), "RpcStringFree\n");
     ok(RPC_S_OK == RpcBindingFree(&IServer_IfHandle), "RpcBindingFree\n");
@@ -1473,7 +1481,8 @@ client(const char *test)
     ok(RPC_S_OK == RpcBindingFromStringBinding(binding, &IServer_IfHandle), "RpcBindingFromStringBinding\n");
 
     run_tests();
-    authinfo_test(RPC_PROTSEQ_NMP, 0);
+    if (pGetUserNameExA)
+      authinfo_test(RPC_PROTSEQ_NMP, 0);
     stop();
 
     ok(RPC_S_OK == RpcStringFree(&binding), "RpcStringFree\n");
@@ -1573,6 +1582,8 @@ START_TEST(server)
     domain_and_user = HeapAlloc(GetProcessHeap(), 0, size);
     ok(pGetUserNameExA(NameSamCompatible, domain_and_user, &size), "GetUserNameExA\n");
   }
+  else
+    win_skip("GetUserNameExA is needed for authentication tests\n");
 
   argc = winetest_get_mainargs(&argv);
   progname = argv[0];