diff --git a/cmake/Modules/MacroQbtCompilerSettings.cmake b/cmake/Modules/MacroQbtCompilerSettings.cmake
index 783457a69..114681c12 100644
--- a/cmake/Modules/MacroQbtCompilerSettings.cmake
+++ b/cmake/Modules/MacroQbtCompilerSettings.cmake
@@ -22,7 +22,7 @@ macro(qbt_set_compiler_options)
     # 		"-Weffc++"
             "-Werror -Wno-error=cpp"
             # we should modify code to make these ones obsolete
-            "-Wno-error=old-style-cast -Wno-error=sign-conversion -Wno-error=float-equal"
+            "-Wno-error=sign-conversion -Wno-error=float-equal"
         )
 
         if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU" AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS 4.9)
diff --git a/src/app/stacktrace.h b/src/app/stacktrace.h
index bb9fb0f05..4bcccf859 100644
--- a/src/app/stacktrace.h
+++ b/src/app/stacktrace.h
@@ -33,7 +33,7 @@ static inline void print_stacktrace(FILE *out = stderr, unsigned int max_frames
 
     // allocate string which will be filled with the demangled function name
     size_t funcnamesize = 256;
-    char *funcname = (char *)malloc(funcnamesize);
+    char *funcname = static_cast<char *>(malloc(funcnamesize));
 
     int functionNamesFound = 0;
     // iterate over the returned symbol lines. skip the first, it is the
diff --git a/src/base/bittorrent/infohash.cpp b/src/base/bittorrent/infohash.cpp
index 293e650fe..0e37c7509 100644
--- a/src/base/bittorrent/infohash.cpp
+++ b/src/base/bittorrent/infohash.cpp
@@ -41,7 +41,7 @@ InfoHash::InfoHash(const libtorrent::sha1_hash &nativeHash)
     , m_nativeHash(nativeHash)
 {
     char out[(libtorrent::sha1_hash::size * 2) + 1];
-    libtorrent::to_hex((char const*)&m_nativeHash[0], libtorrent::sha1_hash::size, out);
+    libtorrent::to_hex(reinterpret_cast<const char*>(&m_nativeHash[0]), libtorrent::sha1_hash::size, out);
     m_hashString = QString(out);
 }
 
@@ -51,7 +51,7 @@ InfoHash::InfoHash(const QString &hashString)
 {
     QByteArray raw = m_hashString.toLatin1();
     if (raw.size() == 40)
-        m_valid = libtorrent::from_hex(raw.constData(), 40, (char*)&m_nativeHash[0]);
+        m_valid = libtorrent::from_hex(raw.constData(), 40, reinterpret_cast<char*>(&m_nativeHash[0]));
 }
 
 
diff --git a/src/base/bittorrent/private/filterparserthread.cpp b/src/base/bittorrent/private/filterparserthread.cpp
index 6b93da05c..a3304815e 100644
--- a/src/base/bittorrent/private/filterparserthread.cpp
+++ b/src/base/bittorrent/private/filterparserthread.cpp
@@ -417,7 +417,7 @@ int FilterParserThread::parseP2BFilterFile()
     unsigned char version;
     if (!stream.readRawData(buf, sizeof(buf))
         || memcmp(buf, "\xFF\xFF\xFF\xFFP2B", 7)
-        || !stream.readRawData((char*)&version, sizeof(version))) {
+        || !stream.readRawData(reinterpret_cast<char*>(&version), sizeof(version))) {
         LogMsg(tr("Parsing Error: The filter file is not a valid PeerGuardian P2B file."), Log::CRITICAL);
         return ruleCount;
     }
@@ -428,8 +428,8 @@ int FilterParserThread::parseP2BFilterFile()
 
         std::string name;
         while(getlineInStream(stream, name, '\0') && !m_abort) {
-            if (!stream.readRawData((char*)&start, sizeof(start))
-                || !stream.readRawData((char*)&end, sizeof(end))) {
+            if (!stream.readRawData(reinterpret_cast<char*>(&start), sizeof(start))
+                || !stream.readRawData(reinterpret_cast<char*>(&end), sizeof(end))) {
                 LogMsg(tr("Parsing Error: The filter file is not a valid PeerGuardian P2B file."), Log::CRITICAL);
                 return ruleCount;
             }
@@ -450,7 +450,7 @@ int FilterParserThread::parseP2BFilterFile()
     else if (version == 3) {
         qDebug ("p2b version 3");
         unsigned int namecount;
-        if (!stream.readRawData((char*)&namecount, sizeof(namecount))) {
+        if (!stream.readRawData(reinterpret_cast<char*>(&namecount), sizeof(namecount))) {
             LogMsg(tr("Parsing Error: The filter file is not a valid PeerGuardian P2B file."), Log::CRITICAL);
             return ruleCount;
         }
@@ -469,7 +469,7 @@ int FilterParserThread::parseP2BFilterFile()
 
         // Reading the ranges
         unsigned int rangecount;
-        if (!stream.readRawData((char*)&rangecount, sizeof(rangecount))) {
+        if (!stream.readRawData(reinterpret_cast<char*>(&rangecount), sizeof(rangecount))) {
             LogMsg(tr("Parsing Error: The filter file is not a valid PeerGuardian P2B file."), Log::CRITICAL);
             return ruleCount;
         }
@@ -477,9 +477,9 @@ int FilterParserThread::parseP2BFilterFile()
         rangecount = ntohl(rangecount);
         unsigned int name, start, end;
         for (unsigned int i = 0; i < rangecount; ++i) {
-            if (!stream.readRawData((char*)&name, sizeof(name))
-                || !stream.readRawData((char*)&start, sizeof(start))
-                || !stream.readRawData((char*)&end, sizeof(end))) {
+            if (!stream.readRawData(reinterpret_cast<char*>(&name), sizeof(name))
+                || !stream.readRawData(reinterpret_cast<char*>(&start), sizeof(start))
+                || !stream.readRawData(reinterpret_cast<char*>(&end), sizeof(end))) {
                 LogMsg(tr("Parsing Error: The filter file is not a valid PeerGuardian P2B file."), Log::CRITICAL);
                 return ruleCount;
             }
diff --git a/src/base/bittorrent/torrenthandle.cpp b/src/base/bittorrent/torrenthandle.cpp
index bb9ec3739..ac899faa6 100644
--- a/src/base/bittorrent/torrenthandle.cpp
+++ b/src/base/bittorrent/torrenthandle.cpp
@@ -555,7 +555,7 @@ qreal TorrentHandle::progress() const
     if (m_nativeStatus.total_wanted_done == m_nativeStatus.total_wanted)
         return 1.;
 
-    float progress = (float) m_nativeStatus.total_wanted_done / (float) m_nativeStatus.total_wanted;
+    float progress = static_cast<float>(m_nativeStatus.total_wanted_done) / m_nativeStatus.total_wanted;
     Q_ASSERT((progress >= 0.f) && (progress <= 1.f));
     return progress;
 }
diff --git a/src/base/filesystemwatcher.cpp b/src/base/filesystemwatcher.cpp
index 3eead127d..c4877ee08 100644
--- a/src/base/filesystemwatcher.cpp
+++ b/src/base/filesystemwatcher.cpp
@@ -224,7 +224,9 @@ bool FileSystemWatcher::isNetworkFileSystem(QString path)
         // XXX: should we make sure HAVE_STRUCT_FSSTAT_F_FSTYPENAME is defined?
         return ((strcmp(buf.f_fstypename, "nfs") == 0) || (strcmp(buf.f_fstypename, "cifs") == 0) || (strcmp(buf.f_fstypename, "smbfs") == 0));
 #else
-        return ((buf.f_type == (long)CIFS_MAGIC_NUMBER) || (buf.f_type == (long)NFS_SUPER_MAGIC) || (buf.f_type == (long)SMB_SUPER_MAGIC));
+        return ((buf.f_type == static_cast<long>(CIFS_MAGIC_NUMBER))
+            || (buf.f_type == static_cast<long>(NFS_SUPER_MAGIC))
+            || (buf.f_type == static_cast<long>(SMB_SUPER_MAGIC)));
 #endif
     }
     else {
diff --git a/src/base/net/private/geoipdatabase.cpp b/src/base/net/private/geoipdatabase.cpp
index 8dec63742..9594ac929 100644
--- a/src/base/net/private/geoipdatabase.cpp
+++ b/src/base/net/private/geoipdatabase.cpp
@@ -105,7 +105,7 @@ GeoIPDatabase *GeoIPDatabase::load(const QString &filename, QString &error)
 
     db = new GeoIPDatabase(file.size());
 
-    if (file.read((char *)db->m_data, db->m_size) != db->m_size) {
+    if (file.read(reinterpret_cast<char *>(db->m_data), db->m_size) != db->m_size) {
         error = file.errorString();
         delete db;
         return 0;
@@ -130,7 +130,7 @@ GeoIPDatabase *GeoIPDatabase::load(const QByteArray &data, QString &error)
 
     db = new GeoIPDatabase(data.size());
 
-    memcpy((char *)db->m_data, data.constData(), db->m_size);
+    memcpy(reinterpret_cast<char *>(db->m_data), data.constData(), db->m_size);
 
     if (!db->parseMetadata(db->readMetadata(), error) || !db->loadDB(error)) {
         delete db;
diff --git a/src/base/preferences.cpp b/src/base/preferences.cpp
index bf376b676..810413620 100644
--- a/src/base/preferences.cpp
+++ b/src/base/preferences.cpp
@@ -406,12 +406,12 @@ void Preferences::setSchedulerEndTime(const QTime &time)
 
 scheduler_days Preferences::getSchedulerDays() const
 {
-    return (scheduler_days)value("Preferences/Scheduler/days", EVERY_DAY).toInt();
+    return static_cast<scheduler_days>(value("Preferences/Scheduler/days", EVERY_DAY).toInt());
 }
 
 void Preferences::setSchedulerDays(scheduler_days days)
 {
-    setValue("Preferences/Scheduler/days", (int)days);
+    setValue("Preferences/Scheduler/days", static_cast<int>(days));
 }
 
 // Search
diff --git a/src/base/utils/random.cpp b/src/base/utils/random.cpp
index cb8e3e250..add0b4e16 100644
--- a/src/base/utils/random.cpp
+++ b/src/base/utils/random.cpp
@@ -56,7 +56,7 @@ uint32_t Utils::Random::rand(const uint32_t min, const uint32_t max)
     static thread_local std::mt19937 generator{
         hasTrueRandomDevice
         ? std::random_device{}()
-        : (std::random_device::result_type) std::chrono::system_clock::now().time_since_epoch().count()
+        : static_cast<std::random_device::result_type>(std::chrono::system_clock::now().time_since_epoch().count())
     };
 #endif
 
diff --git a/src/gui/mainwindow.cpp b/src/gui/mainwindow.cpp
index 1e54f37b8..06c38df00 100644
--- a/src/gui/mainwindow.cpp
+++ b/src/gui/mainwindow.cpp
@@ -1092,7 +1092,7 @@ bool MainWindow::event(QEvent *e)
         if (isMinimized()) {
             qDebug("minimisation");
             if (m_systrayIcon && Preferences::instance()->minimizeToTray()) {
-                qDebug("Has active window: %d", (int)(qApp->activeWindow() != 0));
+                qDebug() << "Has active window:" << (qApp->activeWindow() != nullptr);
                 // Check if there is a modal window
                 bool hasModalWindow = false;
                 foreach (QWidget *widget, QApplication::allWidgets()) {
diff --git a/src/gui/messageboxraised.cpp b/src/gui/messageboxraised.cpp
index ac427e77f..902697628 100644
--- a/src/gui/messageboxraised.cpp
+++ b/src/gui/messageboxraised.cpp
@@ -37,7 +37,7 @@ MessageBoxRaised::MessageBoxRaised(QMessageBox::Icon icon, const QString &title,
 QMessageBox::StandardButton MessageBoxRaised::impl(const QMessageBox::Icon &icon, QWidget *parent, const QString &title, const QString &text, QMessageBox::StandardButtons buttons, QMessageBox::StandardButton defaultButton) {
   MessageBoxRaised dlg(icon, title, text, buttons, parent);
   dlg.setDefaultButton(defaultButton);
-  return (QMessageBox::StandardButton)dlg.exec();
+  return static_cast<QMessageBox::StandardButton>(dlg.exec());
 }
 
 QMessageBox::StandardButton MessageBoxRaised::critical(QWidget *parent, const QString &title, const QString &text, QMessageBox::StandardButtons buttons, QMessageBox::StandardButton defaultButton) {
diff --git a/src/gui/optionsdlg.cpp b/src/gui/optionsdlg.cpp
index 2b3835ad8..3513c954a 100644
--- a/src/gui/optionsdlg.cpp
+++ b/src/gui/optionsdlg.cpp
@@ -577,7 +577,7 @@ void OptionsDialog::saveOptions()
     session->setBandwidthSchedulerEnabled(m_ui->check_schedule->isChecked());
     pref->setSchedulerStartTime(m_ui->schedule_from->time());
     pref->setSchedulerEndTime(m_ui->schedule_to->time());
-    pref->setSchedulerDays((scheduler_days)m_ui->schedule_days->currentIndex());
+    pref->setSchedulerDays(static_cast<scheduler_days>(m_ui->schedule_days->currentIndex()));
 
     auto proxyConfigManager  = Net::ProxyConfigurationManager::instance();
     Net::ProxyConfiguration proxyConf;
@@ -967,7 +967,7 @@ void OptionsDialog::loadOptions()
     m_ui->check_schedule->setChecked(session->isBandwidthSchedulerEnabled());
     m_ui->schedule_from->setTime(pref->getSchedulerStartTime());
     m_ui->schedule_to->setTime(pref->getSchedulerEndTime());
-    m_ui->schedule_days->setCurrentIndex((int)pref->getSchedulerDays());
+    m_ui->schedule_days->setCurrentIndex(static_cast<int>(pref->getSchedulerDays()));
     // End Speed preferences
 
     // Bittorrent preferences
@@ -1024,7 +1024,7 @@ void OptionsDialog::loadOptions()
     m_ui->checkBypassLocalAuth->setChecked(!pref->isWebUiLocalAuthEnabled());
 
     m_ui->checkDynDNS->setChecked(pref->isDynDNSEnabled());
-    m_ui->comboDNSService->setCurrentIndex((int)pref->getDynDNSService());
+    m_ui->comboDNSService->setCurrentIndex(static_cast<int>(pref->getDynDNSService()));
     m_ui->domainNameTxt->setText(pref->getDynDomainName());
     m_ui->DNSUsernameTxt->setText(pref->getDynDNSUsername());
     m_ui->DNSPasswordTxt->setText(pref->getDynDNSPassword());
diff --git a/src/gui/powermanagement/powermanagement_x11.cpp b/src/gui/powermanagement/powermanagement_x11.cpp
index b5bd2196c..14958a62f 100644
--- a/src/gui/powermanagement/powermanagement_x11.cpp
+++ b/src/gui/powermanagement/powermanagement_x11.cpp
@@ -117,9 +117,9 @@ void PowerManagementInhibitor::RequestBusy()
 
     QList<QVariant> args;
     args << "qBittorrent";
-    if (m_use_gsm) args << (uint)0;
+    if (m_use_gsm) args << 0u;
     args << "Active torrents are presented";
-    if (m_use_gsm) args << (uint)8;
+    if (m_use_gsm) args << 8u;
     call.setArguments(args);
 
     QDBusPendingCall pcall = QDBusConnection::sessionBus().asyncCall(call, 1000);
diff --git a/src/gui/previewlistdelegate.h b/src/gui/previewlistdelegate.h
index 7a42653c3..6dfb085ce 100644
--- a/src/gui/previewlistdelegate.h
+++ b/src/gui/previewlistdelegate.h
@@ -67,7 +67,7 @@ class PreviewListDelegate: public QItemDelegate {
           qreal progress = index.data().toDouble()*100.;
           newopt.rect = opt.rect;
           newopt.text = ((progress == 100.0) ? QString("100%") : Utils::String::fromDouble(progress, 1) + "%");
-          newopt.progress = (int)progress;
+          newopt.progress = static_cast<int>(progress);
           newopt.maximum = 100;
           newopt.minimum = 0;
           newopt.state |= QStyle::State_Enabled;
diff --git a/src/gui/properties/pieceavailabilitybar.cpp b/src/gui/properties/pieceavailabilitybar.cpp
index fcbf44bb2..0ce3f2618 100644
--- a/src/gui/properties/pieceavailabilitybar.cpp
+++ b/src/gui/properties/pieceavailabilitybar.cpp
@@ -44,7 +44,7 @@ QVector<float> PieceAvailabilityBar::intToFloatVector(const QVector<int> &vecin,
     QVector<float> result(reqSize, 0.0);
     if (vecin.isEmpty()) return result;
 
-    const float ratio = vecin.size() / (float)reqSize;
+    const float ratio = static_cast<float>(vecin.size()) / reqSize;
 
     const int maxElement = *std::max_element(vecin.begin(), vecin.end());
 
@@ -112,7 +112,7 @@ QVector<float> PieceAvailabilityBar::intToFloatVector(const QVector<int> &vecin,
         value /= ratio * maxElement;
 
         // float precision sometimes gives > 1, because in not possible to store irrational numbers
-        value = qMin(value, (float)1.0);
+        value = qMin(value, 1.0f);
 
         result[x] = value;
     }
diff --git a/src/gui/statsdialog.cpp b/src/gui/statsdialog.cpp
index 50432db33..f73d61164 100644
--- a/src/gui/statsdialog.cpp
+++ b/src/gui/statsdialog.cpp
@@ -71,7 +71,7 @@ void StatsDialog::update()
     // Global ratio
     m_ui->labelGlobalRatio->setText(
                 ((atd > 0) && (atu > 0))
-                ? Utils::String::fromDouble((qreal)atu / (qreal)atd, 2)
+                ? Utils::String::fromDouble(static_cast<qreal>(atu) / atd, 2)
                 : "-");
     // Cache hits
     qreal readRatio = cs.readRatio;
diff --git a/src/gui/torrentcontentmodel.cpp b/src/gui/torrentcontentmodel.cpp
index ace9868a8..bae6d58be 100644
--- a/src/gui/torrentcontentmodel.cpp
+++ b/src/gui/torrentcontentmodel.cpp
@@ -82,9 +82,9 @@ void TorrentContentModel::updateFilesProgress(const QVector<qreal> &fp)
 
 void TorrentContentModel::updateFilesPriorities(const QVector<int> &fprio)
 {
-    Q_ASSERT(m_filesIndex.size() == (int)fprio.size());
+    Q_ASSERT(m_filesIndex.size() == fprio.size());
     // XXX: Why is this necessary?
-    if (m_filesIndex.size() != (int)fprio.size())
+    if (m_filesIndex.size() != fprio.size())
         return;
 
     emit layoutAboutToBeChanged();
diff --git a/src/gui/transferlistdelegate.cpp b/src/gui/transferlistdelegate.cpp
index eb1f8adde..6187cc245 100644
--- a/src/gui/transferlistdelegate.cpp
+++ b/src/gui/transferlistdelegate.cpp
@@ -162,7 +162,7 @@ void TransferListDelegate::paint(QPainter * painter, const QStyleOptionViewItem
         qreal progress = index.data().toDouble() * 100.;
         newopt.rect = opt.rect;
         newopt.text = ((progress == 100.0) ? QString("100%") : Utils::String::fromDouble(progress, 1) + "%");
-        newopt.progress = (int)progress;
+        newopt.progress = static_cast<int>(progress);
         newopt.maximum = 100;
         newopt.minimum = 0;
         newopt.state |= QStyle::State_Enabled;
diff --git a/src/gui/transferlistwidget.cpp b/src/gui/transferlistwidget.cpp
index e2e438466..8f77bef06 100644
--- a/src/gui/transferlistwidget.cpp
+++ b/src/gui/transferlistwidget.cpp
@@ -449,7 +449,7 @@ void TransferListWidget::setDlLimitSelectedTorrents()
     if (!ok) return;
 
     foreach (BitTorrent::TorrentHandle *const torrent, TorrentsList) {
-        qDebug("Applying download speed limit of %ld Kb/s to torrent %s", (long) (newLimit / 1024.), qPrintable(torrent->hash()));
+        qDebug("Applying download speed limit of %ld Kb/s to torrent %s", (newLimit / 1024l), qPrintable(torrent->hash()));
         torrent->setDownloadLimit(newLimit);
     }
 }
@@ -474,7 +474,7 @@ void TransferListWidget::setUpLimitSelectedTorrents()
     if (!ok) return;
 
     foreach (BitTorrent::TorrentHandle *const torrent, TorrentsList) {
-        qDebug("Applying upload speed limit of %ld Kb/s to torrent %s", (long) (newLimit / 1024.), qPrintable(torrent->hash()));
+        qDebug("Applying upload speed limit of %ld Kb/s to torrent %s", (newLimit / 1024l), qPrintable(torrent->hash()));
         torrent->setUploadLimit(newLimit);
     }
 }
diff --git a/src/webui/btjson.cpp b/src/webui/btjson.cpp
index 869221cf7..4eef96403 100644
--- a/src/webui/btjson.cpp
+++ b/src/webui/btjson.cpp
@@ -373,7 +373,7 @@ QByteArray btjson::getSyncMainData(int acceptedResponseId, QVariantMap &lastData
         if (lastData.contains("torrents") && lastData["torrents"].toHash().contains(torrent->hash()) &&
                 lastData["torrents"].toHash()[torrent->hash()].toMap().contains(KEY_TORRENT_LAST_ACTIVITY_TIME)) {
             uint lastValue = lastData["torrents"].toHash()[torrent->hash()].toMap()[KEY_TORRENT_LAST_ACTIVITY_TIME].toUInt();
-            if (qAbs((int)(lastValue - map[KEY_TORRENT_LAST_ACTIVITY_TIME].toUInt())) < 15)
+            if (qAbs(static_cast<int>(lastValue - map[KEY_TORRENT_LAST_ACTIVITY_TIME].toUInt())) < 15)
                 map[KEY_TORRENT_LAST_ACTIVITY_TIME] = lastValue;
         }
 
@@ -595,8 +595,8 @@ QByteArray btjson::getPropertiesForTorrent(const QString& hash)
     dataDict[KEY_PROP_CREATED_BY] = torrent->creator();
     dataDict[KEY_PROP_ADDITION_DATE] = torrent->addedTime().toTime_t();
     if (torrent->hasMetadata()) {
-        dataDict[KEY_PROP_LAST_SEEN] = torrent->lastSeenComplete().isValid() ? (int)torrent->lastSeenComplete().toTime_t() : -1;
-        dataDict[KEY_PROP_COMPLETION_DATE] = torrent->completedTime().isValid() ? (int)torrent->completedTime().toTime_t() : -1;
+        dataDict[KEY_PROP_LAST_SEEN] = torrent->lastSeenComplete().isValid() ? static_cast<int>(torrent->lastSeenComplete().toTime_t()) : -1;
+        dataDict[KEY_PROP_COMPLETION_DATE] = torrent->completedTime().isValid() ? static_cast<int>(torrent->completedTime().toTime_t()) : -1;
         dataDict[KEY_PROP_CREATION_DATE] = torrent->creationDate().toTime_t();
     }
     else {
@@ -743,7 +743,7 @@ QVariantMap getTranserInfoMap()
     map[KEY_TRANSFER_ALLTIME_DL] = atd;
     map[KEY_TRANSFER_ALLTIME_UL] = atu;
     map[KEY_TRANSFER_TOTAL_WASTE_SESSION] = sessionStatus.totalWasted;
-    map[KEY_TRANSFER_GLOBAL_RATIO] = ( atd > 0 && atu > 0 ) ? Utils::String::fromDouble((qreal)atu / (qreal)atd, 2) : "-";
+    map[KEY_TRANSFER_GLOBAL_RATIO] = ( atd > 0 && atu > 0 ) ? Utils::String::fromDouble(static_cast<qreal>(atu) / atd, 2) : "-";
     map[KEY_TRANSFER_TOTAL_PEER_CONNECTIONS] = sessionStatus.peersCount;
 
     qreal readRatio = cacheStatus.readRatio;