diff --git a/src/emojis.cpp b/src/emojis.cpp
index 329e5717..3aad860a 100644
--- a/src/emojis.cpp
+++ b/src/emojis.cpp
@@ -42,7 +42,7 @@ void Emojis::parseEmojis(std::vector<std::tuple<messages::LazyLoadedImage *, QSt
 
                         if (i - lastSlice != 0) {
                             vector.push_back(std::tuple<messages::LazyLoadedImage *, QString>(
-                                NULL, text.mid(lastSlice, i - lastSlice)));
+                                nullptr, text.mid(lastSlice, i - lastSlice)));
                         }
 
                         vector.push_back(std::tuple<messages::LazyLoadedImage *, QString>(
@@ -63,7 +63,7 @@ void Emojis::parseEmojis(std::vector<std::tuple<messages::LazyLoadedImage *, QSt
 
     if (lastSlice < text.length()) {
         vector.push_back(
-            std::tuple<messages::LazyLoadedImage *, QString>(NULL, text.mid(lastSlice)));
+            std::tuple<messages::LazyLoadedImage *, QString>(nullptr, text.mid(lastSlice)));
     }
 }
 
diff --git a/src/ircmanager.cpp b/src/ircmanager.cpp
index c39a4dab..b2a3eea0 100644
--- a/src/ircmanager.cpp
+++ b/src/ircmanager.cpp
@@ -254,7 +254,7 @@ void IrcManager::privateMessageReceived(Communi::IrcPrivateMessage *message)
 {
     auto c = ChannelManager::getInstance().getChannel(message->target().mid(1));
 
-    if (c != NULL) {
+    if (c != nullptr) {
         messages::MessageParseArgs args;
 
         c->addMessage(twitch::TwitchMessageBuilder::parse(message, c.get(), args));
diff --git a/src/messages/lazyloadedimage.cpp b/src/messages/lazyloadedimage.cpp
index 3a9b7238..1502be22 100644
--- a/src/messages/lazyloadedimage.cpp
+++ b/src/messages/lazyloadedimage.cpp
@@ -20,7 +20,7 @@ namespace messages {
 
 LazyLoadedImage::LazyLoadedImage(const QString &url, qreal scale, const QString &name,
                                  const QString &tooltip, const QMargins &margin, bool isHat)
-    : _currentPixmap(NULL)
+    : _currentPixmap(nullptr)
     , _currentFrame(0)
     , _currentFrameOffset(0)
     , _url(url)
diff --git a/src/messages/lazyloadedimage.hpp b/src/messages/lazyloadedimage.hpp
index 8e64d8df..5397e14a 100644
--- a/src/messages/lazyloadedimage.hpp
+++ b/src/messages/lazyloadedimage.hpp
@@ -63,7 +63,7 @@ public:
 
     int getWidth() const
     {
-        if (_currentPixmap == NULL) {
+        if (_currentPixmap == nullptr) {
             return 16;
         }
         return _currentPixmap->width();
@@ -71,7 +71,7 @@ public:
 
     int getHeight() const
     {
-        if (_currentPixmap == NULL) {
+        if (_currentPixmap == nullptr) {
             return 16;
         }
         return _currentPixmap->height();
diff --git a/src/messages/word.cpp b/src/messages/word.cpp
index 46d93bbf..7a9a4434 100644
--- a/src/messages/word.cpp
+++ b/src/messages/word.cpp
@@ -22,7 +22,7 @@ Word::Word(LazyLoadedImage *image, Type type, const QString &copytext, const QSt
 // Text word
 Word::Word(const QString &text, Type type, const QColor &color, const QString &copytext,
            const QString &tooltip, const Link &link)
-    : _image(NULL)
+    : _image(nullptr)
     , _text(text)
     , _color(color)
     , _isImage(false)
diff --git a/src/resources.cpp b/src/resources.cpp
index 6c399499..fc31b563 100644
--- a/src/resources.cpp
+++ b/src/resources.cpp
@@ -4,23 +4,23 @@
 
 namespace chatterino {
 
-messages::LazyLoadedImage *Resources::badgeStaff(NULL);
-messages::LazyLoadedImage *Resources::badgeAdmin(NULL);
-messages::LazyLoadedImage *Resources::badgeModerator(NULL);
-messages::LazyLoadedImage *Resources::badgeGlobalmod(NULL);
-messages::LazyLoadedImage *Resources::badgeTurbo(NULL);
-messages::LazyLoadedImage *Resources::badgeBroadcaster(NULL);
-messages::LazyLoadedImage *Resources::badgePremium(NULL);
+messages::LazyLoadedImage *Resources::badgeStaff(nullptr);
+messages::LazyLoadedImage *Resources::badgeAdmin(nullptr);
+messages::LazyLoadedImage *Resources::badgeModerator(nullptr);
+messages::LazyLoadedImage *Resources::badgeGlobalmod(nullptr);
+messages::LazyLoadedImage *Resources::badgeTurbo(nullptr);
+messages::LazyLoadedImage *Resources::badgeBroadcaster(nullptr);
+messages::LazyLoadedImage *Resources::badgePremium(nullptr);
 
-messages::LazyLoadedImage *Resources::cheerBadge100000(NULL);
-messages::LazyLoadedImage *Resources::cheerBadge10000(NULL);
-messages::LazyLoadedImage *Resources::cheerBadge5000(NULL);
-messages::LazyLoadedImage *Resources::cheerBadge1000(NULL);
-messages::LazyLoadedImage *Resources::cheerBadge100(NULL);
-messages::LazyLoadedImage *Resources::cheerBadge1(NULL);
+messages::LazyLoadedImage *Resources::cheerBadge100000(nullptr);
+messages::LazyLoadedImage *Resources::cheerBadge10000(nullptr);
+messages::LazyLoadedImage *Resources::cheerBadge5000(nullptr);
+messages::LazyLoadedImage *Resources::cheerBadge1000(nullptr);
+messages::LazyLoadedImage *Resources::cheerBadge100(nullptr);
+messages::LazyLoadedImage *Resources::cheerBadge1(nullptr);
 
-messages::LazyLoadedImage *Resources::buttonBan(NULL);
-messages::LazyLoadedImage *Resources::buttonTimeout(NULL);
+messages::LazyLoadedImage *Resources::buttonBan(nullptr);
+messages::LazyLoadedImage *Resources::buttonTimeout(nullptr);
 
 Resources::Resources()
 {
diff --git a/src/twitch/twitchmessagebuilder.cpp b/src/twitch/twitchmessagebuilder.cpp
index 77b76587..2bc62d00 100644
--- a/src/twitch/twitchmessagebuilder.cpp
+++ b/src/twitch/twitchmessagebuilder.cpp
@@ -21,7 +21,7 @@ void TwitchMessageBuilder::appendTwitchBadges(const QStringList &badges)
 {
     for (QString badge : badges) {
         if (badge.startsWith("bits/")) {
-            long long int cheer = std::strtoll(badge.mid(5).toStdString().c_str(), NULL, 10);
+            long long int cheer = std::strtoll(badge.mid(5).toStdString().c_str(), nullptr, 10);
             appendWord(Word(EmoteManager::getInstance().getCheerBadge(cheer), Word::BadgeCheer,
                             QString(), QString("Twitch Cheer" + QString::number(cheer))));
         } else if (badge == "staff/1") {
@@ -166,7 +166,7 @@ SharedMessage TwitchMessageBuilder::parse(const Communi::IrcPrivateMessage *ircM
             if (parameters.length() < 2)
                 continue;
 
-            long int id = std::stol(parameters.at(0).toStdString(), NULL, 10);
+            long int id = std::stol(parameters.at(0).toStdString(), nullptr, 10);
 
             QStringList occurences = parameters.at(1).split(',');
 
@@ -176,8 +176,8 @@ SharedMessage TwitchMessageBuilder::parse(const Communi::IrcPrivateMessage *ircM
                 if (coords.length() < 2)
                     continue;
 
-                long int start = std::stol(coords.at(0).toStdString(), NULL, 10);
-                long int end = std::stol(coords.at(1).toStdString(), NULL, 10);
+                long int start = std::stol(coords.at(0).toStdString(), nullptr, 10);
+                long int end = std::stol(coords.at(1).toStdString(), nullptr, 10);
 
                 if (start >= end || start < 0 || end > ircMessage->content().length())
                     continue;
@@ -235,7 +235,7 @@ SharedMessage TwitchMessageBuilder::parse(const Communi::IrcPrivateMessage *ircM
         for (const std::tuple<LazyLoadedImage *, QString> &tuple : parsed) {
             LazyLoadedImage *image = std::get<0>(tuple);
 
-            if (image == NULL) {  // is text
+            if (image == nullptr) {  // is text
                 QString string = std::get<1>(tuple);
 
                 static QRegularExpression cheerRegex("cheer[1-9][0-9]*");
diff --git a/src/twitch/twitchparsemessage.cpp b/src/twitch/twitchparsemessage.cpp
index 6332197b..8c3bd82b 100644
--- a/src/twitch/twitchparsemessage.cpp
+++ b/src/twitch/twitchparsemessage.cpp
@@ -137,7 +137,7 @@
 //            if (parameters.length() < 2)
 //                continue;
 //
-//            long int id = std::stol(parameters.at(0).toStdString(), NULL, 10);
+//            long int id = std::stol(parameters.at(0).toStdString(), nullptr, 10);
 //
 //            QStringList occurences = parameters.at(1).split(',');
 //
@@ -148,8 +148,8 @@
 //                    continue;
 //
 //                long int start =
-//                    std::stol(coords.at(0).toStdString(), NULL, 10);
-//                long int end = std::stol(coords.at(1).toStdString(), NULL,
+//                    std::stol(coords.at(0).toStdString(), nullptr, 10);
+//                long int end = std::stol(coords.at(1).toStdString(), nullptr,
 //                10);
 //
 //                if (start >= end || start < 0 ||
@@ -209,7 +209,7 @@
 //        for (const std::tuple<LazyLoadedImage *, QString> &tuple : parsed) {
 //            LazyLoadedImage *image = std::get<0>(tuple);
 //
-//            if (image == NULL) {  // is text
+//            if (image == nullptr) {  // is text
 //                QString string = std::get<1>(tuple);
 //
 //                static QRegularExpression cheerRegex("cheer[1-9][0-9]*");
diff --git a/src/widgets/mainwindow.cpp b/src/widgets/mainwindow.cpp
index 86a37617..aaa819f1 100644
--- a/src/widgets/mainwindow.cpp
+++ b/src/widgets/mainwindow.cpp
@@ -65,7 +65,7 @@ void MainWindow::layoutVisibleChatWidgets(Channel *channel)
 {
     auto *page = _notebook.getSelectedPage();
 
-    if (page == NULL) {
+    if (page == nullptr) {
         return;
     }
 
@@ -74,7 +74,7 @@ void MainWindow::layoutVisibleChatWidgets(Channel *channel)
     for (auto it = widgets.begin(); it != widgets.end(); ++it) {
         ChatWidget *widget = *it;
 
-        if (channel == NULL || channel == widget->getChannel().get()) {
+        if (channel == nullptr || channel == widget->getChannel().get()) {
             widget->layoutMessages();
         }
     }
@@ -84,7 +84,7 @@ void MainWindow::repaintVisibleChatWidgets(Channel *channel)
 {
     auto *page = _notebook.getSelectedPage();
 
-    if (page == NULL) {
+    if (page == nullptr) {
         return;
     }
 
@@ -93,7 +93,7 @@ void MainWindow::repaintVisibleChatWidgets(Channel *channel)
     for (auto it = widgets.begin(); it != widgets.end(); ++it) {
         ChatWidget *widget = *it;
 
-        if (channel == NULL || channel == widget->getChannel().get()) {
+        if (channel == nullptr || channel == widget->getChannel().get()) {
             widget->layoutMessages();
         }
     }
@@ -103,7 +103,7 @@ void MainWindow::repaintGifEmotes()
 {
     auto *page = _notebook.getSelectedPage();
 
-    if (page == NULL) {
+    if (page == nullptr) {
         return;
     }
 
diff --git a/src/widgets/notebook.cpp b/src/widgets/notebook.cpp
index 960ad797..c849b093 100644
--- a/src/widgets/notebook.cpp
+++ b/src/widgets/notebook.cpp
@@ -67,7 +67,7 @@ void Notebook::removePage(NotebookPage *page)
     int index = _pages.indexOf(page);
 
     if (_pages.size() == 1) {
-        select(NULL);
+        select(nullptr);
     } else if (index == _pages.count() - 1) {
         select(_pages[index - 1]);
     } else {
diff --git a/src/widgets/notebooktab.cpp b/src/widgets/notebooktab.cpp
index d31aadbd..b70e901e 100644
--- a/src/widgets/notebooktab.cpp
+++ b/src/widgets/notebooktab.cpp
@@ -98,7 +98,7 @@ void NotebookTab::moveAnimated(QPoint pos, bool animated)
 {
     _posAnimationDesired = pos;
 
-    if ((window() != NULL && !window()->isVisible()) || !animated || _posAnimated == false) {
+    if ((window() != nullptr && !window()->isVisible()) || !animated || _posAnimated == false) {
         move(pos);
 
         _posAnimated = true;
diff --git a/src/widgets/scrollbar.cpp b/src/widgets/scrollbar.cpp
index 86eb3dee..0049f5be 100644
--- a/src/widgets/scrollbar.cpp
+++ b/src/widgets/scrollbar.cpp
@@ -41,7 +41,7 @@ ScrollBar::~ScrollBar()
 {
     auto highlight = _highlights;
 
-    while (highlight != NULL) {
+    while (highlight != nullptr) {
         auto tmp = highlight->next;
         delete highlight;
         highlight = tmp;
@@ -52,12 +52,12 @@ void ScrollBar::removeHighlightsWhere(std::function<bool(ScrollBarHighlight &)>
 {
     _mutex.lock();
 
-    ScrollBarHighlight *last = NULL;
+    ScrollBarHighlight *last = nullptr;
     ScrollBarHighlight *current = _highlights;
 
-    while (current != NULL) {
+    while (current != nullptr) {
         if (func(*current)) {
-            if (last == NULL) {
+            if (last == nullptr) {
                 _highlights = current->next;
             } else {
                 last->next = current->next;
@@ -79,7 +79,7 @@ void ScrollBar::addHighlight(ScrollBarHighlight *highlight)
 {
     _mutex.lock();
 
-    if (_highlights == NULL) {
+    if (_highlights == nullptr) {
         _highlights = highlight;
     } else {
         highlight->next = _highlights->next;
@@ -224,7 +224,7 @@ void ScrollBar::paintEvent(QPaintEvent *)
 
     //    do {
     //        painter.fillRect();
-    //    } while ((highlight = highlight->next()) != NULL);
+    //    } while ((highlight = highlight->next()) != nullptr);
 
     _mutex.unlock();
 }
diff --git a/src/widgets/settingsdialog.cpp b/src/widgets/settingsdialog.cpp
index 66951fec..a70c36ea 100644
--- a/src/widgets/settingsdialog.cpp
+++ b/src/widgets/settingsdialog.cpp
@@ -289,7 +289,7 @@ void SettingsDialog::select(SettingsDialogTab *tab)
 {
     _pageStack.setCurrentWidget(tab->getWidget());
 
-    if (_selectedTab != NULL) {
+    if (_selectedTab != nullptr) {
         _selectedTab->setSelected(false);
         _selectedTab->setStyleSheet("color: #FFF");
     }
diff --git a/src/widgets/settingsdialog.hpp b/src/widgets/settingsdialog.hpp
index 4fdd9033..6fd04f0c 100644
--- a/src/widgets/settingsdialog.hpp
+++ b/src/widgets/settingsdialog.hpp
@@ -42,7 +42,7 @@ private:
 
     void addTabs();
 
-    SettingsDialogTab *_selectedTab = NULL;
+    SettingsDialogTab *_selectedTab = nullptr;
 
     /// Widget creation helpers
     QCheckBox *createCheckbox(const QString &title, Setting<bool> &setting);
diff --git a/src/widgets/textinputdialog.hpp b/src/widgets/textinputdialog.hpp
index 1e62ac41..4cf33c59 100644
--- a/src/widgets/textinputdialog.hpp
+++ b/src/widgets/textinputdialog.hpp
@@ -15,7 +15,7 @@ class TextInputDialog : public QDialog
     Q_OBJECT
 
 public:
-    TextInputDialog(QWidget *parent = NULL);
+    TextInputDialog(QWidget *parent = nullptr);
 
     QString getText() const
     {