diff --git a/client/DigiDoc.cpp b/client/DigiDoc.cpp
index c510ad092..092686105 100644
--- a/client/DigiDoc.cpp
+++ b/client/DigiDoc.cpp
@@ -519,7 +519,7 @@ bool DigiDoc::open( const QString &file )
 
 	try {
 		WaitDialogHolder waitDialog(parent, tr("Opening"), false);
-		waitFor([&] {
+		return waitFor([&] {
 			b = Container::openPtr(to(file));
 			if(b && b->mediaType() == "application/vnd.etsi.asic-s+zip" && b->dataFiles().size() == 1)
 			{
@@ -548,10 +548,10 @@ bool DigiDoc::open( const QString &file )
 				isTimeStamped = parentContainer->signatures()[0]->trustedSigningTime().compare("2018-07-01T00:00:00Z") < 0;
 			for(const Signature *signature: b->signatures())
 				m_signatures.append(DigiDocSignature(signature, this, isTimeStamped));
+			qApp->addRecent( file );
+			containerState = signatures().isEmpty() ? ContainerState::UnsignedSavedContainer : ContainerState::SignedContainer;
+			return true;
 		});
-		qApp->addRecent( file );
-		containerState = signatures().isEmpty() ? ContainerState::UnsignedSavedContainer : ContainerState::SignedContainer;
-		return true;
 	} catch(const Exception &e) {
 		switch(e.code())
 		{
@@ -602,9 +602,9 @@ void DigiDoc::removeSignature( unsigned int num )
 	if( !checkDoc( num >= b->signatures().size(), tr("Missing signature") ) )
 		return;
 	try {
-		waitFor([this, num] {
+		modified = waitFor([this, num] {
 			b->removeSignature(num);
-			modified = true;
+			return true;
 		});
 	}
 	catch( const Exception &e ) { setLastError( tr("Failed remove signature from container"), e ); }
@@ -626,13 +626,13 @@ bool DigiDoc::saveAs(const QString &filename)
 {
 	try
 	{
-		waitFor([&]{
+		return waitFor([&]{
 			if(parentContainer)
 				parentContainer->save(to(filename));
 			else
 				b->save(to(filename));
+			return true;
 		});
-		return true;
 	}
 	catch( const Exception &e ) {
 		QFile::remove(filename);
diff --git a/client/QSigner.cpp b/client/QSigner.cpp
index b48f768be..c220a9ff5 100644
--- a/client/QSigner.cpp
+++ b/client/QSigner.cpp
@@ -46,8 +46,8 @@ Q_LOGGING_CATEGORY(SLog, "qdigidoc4.QSigner")
 class QSigner::Private final
 {
 public:
-	QCryptoBackend	*backend = nullptr;
-	QSmartCard		*smartcard = nullptr;
+	QCryptoBackend	*backend {};
+	QSmartCard		*smartcard {};
 	TokenData		auth, sign;
 	QList<TokenData> cache;
 
@@ -61,7 +61,7 @@ ECDSA_SIG* QSigner::Private::ecdsa_do_sign(const unsigned char *dgst, int dgst_l
 		const BIGNUM * /*inv*/, const BIGNUM * /*rp*/, EC_KEY *eckey)
 {
 	QCryptoBackend *backend = (QCryptoBackend*)EC_KEY_get_ex_data(eckey, 0);
-	QByteArray result = backend->sign(0, QByteArray::fromRawData((const char*)dgst, dgst_len));
+	QByteArray result = backend->sign(NID_sha256, QByteArray::fromRawData((const char*)dgst, dgst_len));
 	if(result.isEmpty())
 		return nullptr;
 	QByteArray r = result.left(result.size()/2);
@@ -199,9 +199,7 @@ QByteArray QSigner::decrypt(std::function<QByteArray (QCryptoBackend *)> &&func)
 		}
 	} while(status != QCryptoBackend::PinOK);
 	QByteArray result;
-	waitFor([&]{
-		result = func(d->backend);
-	});
+	result = waitFor([&]{ return func(d->backend); });
 	QCardLock::instance().exclusiveUnlock();
 	d->backend->logout();
 	d->smartcard->reload(); // QSmartCard should also know that PIN1 is blocked.
@@ -397,9 +395,8 @@ std::vector<unsigned char> QSigner::sign(const std::string &method, const std::v
 			throwException((tr("Failed to login token") + " " + QCryptoBackend::errorString(status)), Exception::PINFailed)
 		}
 	} while(status != QCryptoBackend::PinOK);
-	QByteArray sig;
-	waitFor([&]{
-		sig = d->backend->sign(type, QByteArray::fromRawData((const char*)digest.data(), int(digest.size())));
+	QByteArray sig = waitFor([&]{
+		return d->backend->sign(type, QByteArray::fromRawData((const char*)digest.data(), int(digest.size())));
 	});
 	QCardLock::instance().exclusiveUnlock();
 	d->backend->logout();
diff --git a/client/QSmartCard.cpp b/client/QSmartCard.cpp
index 28be742bd..d9de65978 100644
--- a/client/QSmartCard.cpp
+++ b/client/QSmartCard.cpp
@@ -113,10 +113,9 @@ QPCSCReader::Result Card::transfer(QPCSCReader *reader, bool verify, const QByte
 	else if(Common::language() == QLatin1String("et")) language = 0x0425;
 	else if(Common::language() == QLatin1String("ru")) language = 0x0419;
 	QPCSCReader::Result result;
-	waitFor([&]{
-		result = reader->transferCTL(apdu, verify, language, QSmartCardData::minPinLen(type), newPINOffset, requestCurrentPIN);
+	return waitFor([&]{
+		return reader->transferCTL(apdu, verify, language, QSmartCardData::minPinLen(type), newPINOffset, requestCurrentPIN);
 	});
-	return result;
 }
 
 
diff --git a/client/Utils.h b/client/Utils.h
index 76f80eb32..671b7fe06 100644
--- a/client/Utils.h
+++ b/client/Utils.h
@@ -25,12 +25,13 @@
 
 namespace {
 	template <typename F>
-	inline void waitFor(F&& function) {
+	inline auto waitFor(F&& function) {
 		std::exception_ptr exception;
+		typename std::invoke_result<F>::type result{};
 		QEventLoop l;
 		std::thread([&]{
 			try {
-				function();
+				result = function();
 			} catch(...) {
 				exception = std::current_exception();
 			}
@@ -39,6 +40,7 @@ namespace {
 		l.exec();
 		if(exception)
 			std::rethrow_exception(exception);
+		return result;
 	}
 
 	inline QString escapeUnicode(const QString &str) {