diff --git a/dlls/cryptowinrt/tests/crypto.c b/dlls/cryptowinrt/tests/crypto.c
index 0ddb1de1823..983af748bed 100644
--- a/dlls/cryptowinrt/tests/crypto.c
+++ b/dlls/cryptowinrt/tests/crypto.c
@@ -37,6 +37,25 @@
 
 #include "wine/test.h"
 
+static HRESULT (WINAPI *pWindowsDeleteString)( HSTRING str );
+static const WCHAR* (WINAPI *pWindowsGetStringRawBuffer)( HSTRING, UINT32* );
+
+static BOOL load_combase_functions(void)
+{
+    HMODULE combase = GetModuleHandleW( L"combase.dll" );
+
+#define LOAD_FUNC(m, f) if (!(p ## f = (void *)GetProcAddress( m, #f ))) goto failed;
+    LOAD_FUNC( combase, WindowsDeleteString );
+    LOAD_FUNC( combase, WindowsGetStringRawBuffer );
+#undef LOAD_FUNC
+
+    return TRUE;
+
+failed:
+    win_skip("Failed to load combase.dll functions, skipping tests\n");
+    return FALSE;
+}
+
 #define check_interface( obj, iid ) check_interface_( __LINE__, obj, iid )
 static void check_interface_( unsigned int line, void *obj, const IID *iid )
 {
@@ -49,6 +68,143 @@ static void check_interface_( unsigned int line, void *obj, const IID *iid )
     IUnknown_Release( unk );
 }
 
+#define check_runtimeclass( a, b ) check_runtimeclass_( __LINE__, (IInspectable *)a, b )
+static void check_runtimeclass_( int line, IInspectable *inspectable, const WCHAR *class_name )
+{
+    const WCHAR *buffer;
+    UINT32 length;
+    HSTRING str;
+    HRESULT hr;
+
+    hr = IInspectable_GetRuntimeClassName( inspectable, &str );
+    ok_(__FILE__, line)( hr == S_OK, "GetRuntimeClassName returned %#lx\n", hr );
+    buffer = pWindowsGetStringRawBuffer( str, &length );
+    ok_(__FILE__, line)( !wcscmp( buffer, class_name ), "got class name %s\n", debugstr_w(buffer) );
+    pWindowsDeleteString( str );
+}
+
+#define check_bool_async( a, b, c, d, e ) check_bool_async_( __LINE__, a, b, c, d, e )
+static void check_bool_async_( int line, IAsyncOperation_boolean *async, UINT32 expect_id, AsyncStatus expect_status,
+                               HRESULT expect_hr, BOOLEAN expect_result )
+{
+    AsyncStatus async_status;
+    IAsyncInfo *async_info;
+    HRESULT hr, async_hr;
+    UINT32 async_id;
+    BOOLEAN result;
+
+    hr = IAsyncOperation_boolean_QueryInterface( async, &IID_IAsyncInfo, (void **)&async_info );
+    ok_(__FILE__, line)( hr == S_OK, "QueryInterface returned %#lx\n", hr );
+
+    async_id = 0xdeadbeef;
+    hr = IAsyncInfo_get_Id( async_info, &async_id );
+    if (expect_status < 4) ok_(__FILE__, line)( hr == S_OK, "get_Id returned %#lx\n", hr );
+    else ok_(__FILE__, line)( hr == E_ILLEGAL_METHOD_CALL, "get_Id returned %#lx\n", hr );
+    if (expect_id) ok_(__FILE__, line)( async_id == expect_id, "got id %u\n", async_id );
+    else trace("Skipping async_id check, got id %u\n", async_id );
+
+    async_status = 0xdeadbeef;
+    hr = IAsyncInfo_get_Status( async_info, &async_status );
+    if (expect_status < 4) ok_(__FILE__, line)( hr == S_OK, "get_Status returned %#lx\n", hr );
+    else ok_(__FILE__, line)( hr == E_ILLEGAL_METHOD_CALL, "get_Status returned %#lx\n", hr );
+    ok_(__FILE__, line)( async_status == expect_status || broken( async_status == Error ), "got status %u\n", async_status );
+
+    async_hr = 0xdeadbeef;
+    hr = IAsyncInfo_get_ErrorCode( async_info, &async_hr );
+    if (expect_status < 4) ok_(__FILE__, line)( hr == S_OK, "get_ErrorCode returned %#lx\n", hr );
+    else ok_(__FILE__, line)( hr == E_ILLEGAL_METHOD_CALL, "get_ErrorCode returned %#lx\n", hr );
+    if (expect_status < 4)
+        todo_wine_if(FAILED(expect_hr)) ok_(__FILE__, line)( async_hr == expect_hr || broken( async_hr == E_INVALIDARG), "got error %#lx\n", async_hr );
+    else ok_(__FILE__, line)( async_hr == E_ILLEGAL_METHOD_CALL, "got error %#lx\n", async_hr );
+
+    IAsyncInfo_Release( async_info );
+
+    result = !expect_result;
+    hr = IAsyncOperation_boolean_GetResults( async, &result );
+    switch (expect_status)
+    {
+    case Completed:
+    case Error:
+        todo_wine_if(FAILED(expect_hr))
+        ok_(__FILE__, line)( hr == expect_hr || broken( hr == E_INVALIDARG ), "GetResults returned %#lx\n", hr );
+        ok_(__FILE__, line)( result == expect_result, "got result %u\n", result );
+        break;
+    case Canceled:
+    case Started:
+    default:
+        ok_(__FILE__, line)( hr == E_ILLEGAL_METHOD_CALL, "GetResults returned %#lx\n", hr );
+        break;
+    }
+}
+
+struct bool_async_handler
+{
+    IAsyncOperationCompletedHandler_boolean IAsyncOperationCompletedHandler_boolean_iface;
+    IAsyncOperation_boolean *async;
+    AsyncStatus status;
+    BOOL invoked;
+    HANDLE event;
+};
+
+static inline struct bool_async_handler *impl_from_IAsyncOperationCompletedHandler_boolean( IAsyncOperationCompletedHandler_boolean *iface )
+{
+    return CONTAINING_RECORD( iface, struct bool_async_handler, IAsyncOperationCompletedHandler_boolean_iface );
+}
+
+static HRESULT WINAPI bool_async_handler_QueryInterface( IAsyncOperationCompletedHandler_boolean *iface, REFIID iid, void **out )
+{
+    if (IsEqualGUID( iid, &IID_IUnknown ) ||
+        IsEqualGUID( iid, &IID_IAgileObject ) ||
+        IsEqualGUID( iid, &IID_IAsyncOperationCompletedHandler_boolean ))
+    {
+        IUnknown_AddRef( iface );
+        *out = iface;
+        return S_OK;
+    }
+
+    trace( "%s not implemented, returning E_NOINTERFACE.\n", debugstr_guid( iid ) );
+    *out = NULL;
+    return E_NOINTERFACE;
+}
+
+static ULONG WINAPI bool_async_handler_AddRef( IAsyncOperationCompletedHandler_boolean *iface )
+{
+    return 2;
+}
+
+static ULONG WINAPI bool_async_handler_Release( IAsyncOperationCompletedHandler_boolean *iface )
+{
+    return 1;
+}
+
+static HRESULT WINAPI bool_async_handler_Invoke( IAsyncOperationCompletedHandler_boolean *iface,
+                                                 IAsyncOperation_boolean *async, AsyncStatus status )
+{
+    struct bool_async_handler *impl = impl_from_IAsyncOperationCompletedHandler_boolean( iface );
+
+    trace( "iface %p, async %p, status %u\n", iface, async, status );
+
+    ok( !impl->invoked, "invoked twice\n" );
+    impl->invoked = TRUE;
+    impl->async = async;
+    impl->status = status;
+    if (impl->event) SetEvent( impl->event );
+
+    return S_OK;
+}
+
+static IAsyncOperationCompletedHandler_booleanVtbl bool_async_handler_vtbl =
+{
+    /*** IUnknown methods ***/
+    bool_async_handler_QueryInterface,
+    bool_async_handler_AddRef,
+    bool_async_handler_Release,
+    /*** IAsyncOperationCompletedHandler<boolean> methods ***/
+    bool_async_handler_Invoke,
+};
+
+static struct bool_async_handler default_bool_async_handler = {{&bool_async_handler_vtbl}};
+
 static void test_CryptobufferStatics(void)
 {
     static const WCHAR *cryptobuffer_statics_name = L"Windows.Security.Cryptography.CryptographicBuffer";
@@ -86,10 +242,15 @@ static void test_CryptobufferStatics(void)
 static void test_Credentials_Statics(void)
 {
     static const WCHAR *credentials_statics_name = L"Windows.Security.Credentials.KeyCredentialManager";
+    IAsyncOperationCompletedHandler_boolean *tmp_handler;
     IKeyCredentialManagerStatics *credentials_statics;
+    struct bool_async_handler bool_async_handler;
+    IAsyncOperation_boolean *bool_async;
     IActivationFactory *factory;
+    IAsyncInfo *async_info;
     HSTRING str;
     HRESULT hr;
+    DWORD ret;
     LONG ref;
 
     hr = WindowsCreateString( credentials_statics_name, wcslen( credentials_statics_name ), &str );
@@ -111,6 +272,51 @@ static void test_Credentials_Statics(void)
     hr = IActivationFactory_QueryInterface( factory, &IID_IKeyCredentialManagerStatics, (void **)&credentials_statics );
     ok( hr == S_OK, "got hr %#lx.\n", hr );
 
+    if (!load_combase_functions()) return;
+
+    hr = IKeyCredentialManagerStatics_IsSupportedAsync( credentials_statics, &bool_async );
+    ok( hr == S_OK, "IsSupportedAsync returned %#lx\n", hr );
+
+    check_interface( bool_async, &IID_IUnknown );
+    check_interface( bool_async, &IID_IInspectable );
+    check_interface( bool_async, &IID_IAgileObject );
+    check_interface( bool_async, &IID_IAsyncInfo );
+    check_interface( bool_async, &IID_IAsyncOperation_boolean );
+    check_runtimeclass( bool_async, L"Windows.Foundation.IAsyncOperation`1<Boolean>" );
+
+    hr = IAsyncOperation_boolean_get_Completed( bool_async, &tmp_handler );
+    ok( hr == S_OK, "get_Completed returned %#lx\n", hr );
+    ok( tmp_handler == NULL, "got handler %p\n", tmp_handler );
+    bool_async_handler = default_bool_async_handler;
+    bool_async_handler.event = CreateEventW( NULL, FALSE, FALSE, NULL );
+    hr = IAsyncOperation_boolean_put_Completed( bool_async, &bool_async_handler.IAsyncOperationCompletedHandler_boolean_iface );
+    ok( hr == S_OK, "put_Completed returned %#lx\n", hr );
+    ret = WaitForSingleObject( bool_async_handler.event, 1000 );
+    ok( !ret, "WaitForSingleObject returned %#lx\n", ret );
+    ret = CloseHandle( bool_async_handler.event );
+    ok( ret, "CloseHandle failed, error %lu\n", GetLastError() );
+    ok( bool_async_handler.invoked, "handler not invoked\n" );
+    ok( bool_async_handler.async == bool_async, "got async %p\n", bool_async_handler.async );
+    ok( bool_async_handler.status == Completed || broken( bool_async_handler.status == Error ), "got status %u\n", bool_async_handler.status );
+    bool_async_handler = default_bool_async_handler;
+    hr = IAsyncOperation_boolean_put_Completed( bool_async, &bool_async_handler.IAsyncOperationCompletedHandler_boolean_iface );
+    ok( hr == E_ILLEGAL_DELEGATE_ASSIGNMENT, "put_Completed returned %#lx\n", hr );
+    ok( !bool_async_handler.invoked, "handler invoked\n" );
+    ok( bool_async_handler.async == NULL, "got async %p\n", bool_async_handler.async );
+    ok( bool_async_handler.status == Started, "got status %u\n", bool_async_handler.status );
+
+    hr = IAsyncOperation_boolean_QueryInterface( bool_async, &IID_IAsyncInfo, (void **)&async_info );
+    ok( hr == S_OK, "QueryInterface returned %#lx\n", hr );
+    hr = IAsyncInfo_Cancel( async_info );
+    ok( hr == S_OK, "Cancel returned %#lx\n", hr );
+    check_bool_async( bool_async, 0, Completed, S_OK, FALSE );
+    hr = IAsyncInfo_Close( async_info );
+    ok( hr == S_OK, "Close returned %#lx\n", hr );
+    check_bool_async( bool_async, 0, 4, S_OK, FALSE );
+    IAsyncInfo_Release( async_info );
+
+    IAsyncOperation_boolean_Release( bool_async );
+
     ref = IKeyCredentialManagerStatics_Release( credentials_statics );
     ok( ref == 2, "got ref %ld.\n", ref );
     ref = IActivationFactory_Release( factory );