diff --git a/src/librssguard/gui/dialogs/formmain.cpp b/src/librssguard/gui/dialogs/formmain.cpp
index 9d3a2cbc1..7a6cee87f 100755
--- a/src/librssguard/gui/dialogs/formmain.cpp
+++ b/src/librssguard/gui/dialogs/formmain.cpp
@@ -133,7 +133,7 @@ QList<QAction*> FormMain::allActions() const {
   actions << m_ui->m_actionRestart;
   actions << m_ui->m_actionQuit;
 
-#if !defined(Q_OS_MAC)
+#if !defined(Q_OS_MACOS)
   actions << m_ui->m_actionFullscreen;
 #endif
 
@@ -141,7 +141,7 @@ QList<QAction*> FormMain::allActions() const {
   actions << m_ui->m_actionSwitchFeedsList;
   actions << m_ui->m_actionSwitchMainWindow;
 
-#if !defined(Q_OS_MAC)
+#if !defined(Q_OS_MACOS)
   actions << m_ui->m_actionSwitchMainMenu;
 #endif
 
@@ -219,7 +219,7 @@ void FormMain::prepareMenus() {
   m_ui->m_menuWebBrowserTabs->removeAction(m_ui->m_actionTabNewWebBrowser);
   m_ui->m_menuWebBrowserTabs->setTitle(tr("Tabs"));
 #endif
-#if defined(Q_OS_MAC)
+#if defined(Q_OS_MACOS)
   m_ui->m_actionSwitchMainMenu->setVisible(false);
   m_ui->m_actionFullscreen->setVisible(false);
 #endif
diff --git a/src/librssguard/gui/dialogs/formupdate.cpp b/src/librssguard/gui/dialogs/formupdate.cpp
index 552ae7c40..13b73165c 100644
--- a/src/librssguard/gui/dialogs/formupdate.cpp
+++ b/src/librssguard/gui/dialogs/formupdate.cpp
@@ -44,7 +44,7 @@ FormUpdate::FormUpdate(QWidget* parent)
 }
 
 bool FormUpdate::isSelfUpdateSupported() const {
-#if defined(Q_OS_WIN) || defined(Q_OS_MAC)
+#if defined(Q_OS_WIN) || defined(Q_OS_MACOS)
   return true;
 #else
   return false;
diff --git a/src/librssguard/gui/tabwidget.cpp b/src/librssguard/gui/tabwidget.cpp
index d5960b5dc..6475ab14a 100644
--- a/src/librssguard/gui/tabwidget.cpp
+++ b/src/librssguard/gui/tabwidget.cpp
@@ -229,7 +229,7 @@ int TabWidget::addBrowser(bool move_after_current, bool make_active, const QUrl&
   int final_index;
   QString browser_tab_name = tr("Web browser");
 
-#if defined (Q_OS_MACOS)
+#if defined (Q_OS_MACOSOS)
   browser_tab_name = browser_tab_name.prepend(QSL("  "));
 #endif
 
@@ -291,7 +291,7 @@ void TabWidget::gotoPreviousTab() {
 }
 
 void TabWidget::indentTabText(int index) {
-#if defined (Q_OS_MACOS)
+#if defined (Q_OS_MACOSOS)
   if (tabBar()->tabType(index) != TabBar::FeedReader && !tabIcon(index).isNull()) {
     // We have closable tab with some icon, fix the title.
     const QString text = tabText(index);
diff --git a/src/librssguard/miscellaneous/iofactory.cpp b/src/librssguard/miscellaneous/iofactory.cpp
index d65202a30..9d82863a5 100755
--- a/src/librssguard/miscellaneous/iofactory.cpp
+++ b/src/librssguard/miscellaneous/iofactory.cpp
@@ -78,7 +78,7 @@ bool IOFactory::startProcessDetached(const QString& program, const QStringList&
   process.setProgram(program);
   process.setArguments(arguments);
 
-#if !defined(Q_OS_MAC)
+#if !defined(Q_OS_MACOS)
   process.setNativeArguments(native_arguments);
 #endif
 
diff --git a/src/librssguard/miscellaneous/settings.cpp b/src/librssguard/miscellaneous/settings.cpp
index 086beffcf..420e7633c 100755
--- a/src/librssguard/miscellaneous/settings.cpp
+++ b/src/librssguard/miscellaneous/settings.cpp
@@ -452,7 +452,7 @@ SettingsProperties Settings::determineProperties() {
 
   // We will use PORTABLE settings only and only if it is available and NON-PORTABLE
   // settings was not initialized before.
-#if defined (Q_OS_LINUX) || defined (Q_OS_ANDROID) || defined (Q_OS_MACOS)
+#if defined (Q_OS_LINUX) || defined (Q_OS_ANDROID) || defined (Q_OS_MACOSOS)
   // DO NOT use portable settings for Linux, it is really not used on that platform.
   const bool will_we_use_portable_settings = false;
 #else
diff --git a/src/librssguard/miscellaneous/systemfactory.cpp b/src/librssguard/miscellaneous/systemfactory.cpp
index fc54ecdf1..72c138847 100644
--- a/src/librssguard/miscellaneous/systemfactory.cpp
+++ b/src/librssguard/miscellaneous/systemfactory.cpp
@@ -33,7 +33,7 @@ SystemFactory::~SystemFactory() = default;
 QRegularExpression SystemFactory::supportedUpdateFiles() {
 #if defined(Q_OS_WIN)
   return QRegularExpression(QSL(".+win.+\\.(exe|7z)"));
-#elif defined(Q_OS_MAC)
+#elif defined(Q_OS_MACOS)
   return QRegularExpression(QSL(".dmg"));
 #elif defined(Q_OS_LINUX)
   return QRegularExpression(QSL(".AppImage"));
diff --git a/src/librssguard/miscellaneous/textfactory.cpp b/src/librssguard/miscellaneous/textfactory.cpp
index cbe748492..36647cb90 100755
--- a/src/librssguard/miscellaneous/textfactory.cpp
+++ b/src/librssguard/miscellaneous/textfactory.cpp
@@ -121,7 +121,7 @@ QString TextFactory::decrypt(const QString& text) {
 QString TextFactory::newline() {
 #if defined(Q_OS_WIN)
   return QSL("\r\n");
-#elif defined(Q_OS_MACOS)
+#elif defined(Q_OS_MACOSOS)
   return QSL("\r");
 #else
   return QSL("\n");
diff --git a/src/rssguard/main.cpp b/src/rssguard/main.cpp
index e77f8e717..1963c35e1 100755
--- a/src/rssguard/main.cpp
+++ b/src/rssguard/main.cpp
@@ -7,7 +7,7 @@
 #include "gui/feedsview.h"
 #include "miscellaneous/application.h"
 
-#if defined (Q_OS_MAC)
+#if defined (Q_OS_MACOS)
 extern void disableWindowTabbing();
 
 #endif
@@ -34,7 +34,7 @@ int main(int argc, char* argv[]) {
   // Ensure that ini format is used as application settings storage on Mac OS.
   QSettings::setDefaultFormat(QSettings::IniFormat);
 
-#if defined (Q_OS_MAC)
+#if defined (Q_OS_MACOS)
   QApplication::setAttribute(Qt::AA_DontShowIconsInMenus);
   disableWindowTabbing();
 #endif