diff --git a/src/lib/base/String.cpp b/src/lib/base/String.cpp
index bc5eb072e..65afd3745 100644
--- a/src/lib/base/String.cpp
+++ b/src/lib/base/String.cpp
@@ -106,7 +106,8 @@ std::string sprintf(const char *fmt, ...)
 {
   char tmp[1024];
   char *buffer = tmp;
-  auto len = (int)(sizeof(tmp) / sizeof(tmp[0]));
+  auto len = static_cast<int>(std::size(tmp));
+
   std::string result;
   while (buffer != nullptr) {
     // try printing into the buffer
diff --git a/src/lib/deskflow/KeyState.cpp b/src/lib/deskflow/KeyState.cpp
index f510af01e..6bc9a4e66 100644
--- a/src/lib/deskflow/KeyState.cpp
+++ b/src/lib/deskflow/KeyState.cpp
@@ -1028,7 +1028,7 @@ void KeyState::addKeypadEntries()
   // map every numpad key to its equivalent non-numpad key if it's not
   // on the keyboard.
   for (int32_t g = 0, n = m_keyMap.getNumGroups(); g < n; ++g) {
-    for (size_t i = 0; i < sizeof(s_numpadTable) / sizeof(s_numpadTable[0]); i += 2) {
+    for (size_t i = 0; i < std::size(s_numpadTable); i += 2) {
       m_keyMap.addKeyCombinationEntry(s_numpadTable[i], g, s_numpadTable + i + 1, 1);
     }
   }
diff --git a/src/lib/gui/ServerConfig.cpp b/src/lib/gui/ServerConfig.cpp
index 3cec3ed9f..80abb54aa 100644
--- a/src/lib/gui/ServerConfig.cpp
+++ b/src/lib/gui/ServerConfig.cpp
@@ -249,8 +249,7 @@ QTextStream &operator<<(QTextStream &outStream, const ServerConfig &config)
   for (int i = 0; i < config.screens().size(); i++) {
     if (!config.screens()[i].isNull()) {
       outStream << "\t" << config.screens()[i].name() << ":" << Qt::endl;
-
-      for (unsigned int j = 0; j < sizeof(neighbourDirs) / sizeof(neighbourDirs[0]); j++) {
+      for (unsigned int j = 0; j < std::size(neighbourDirs); j++) {
         int idx = config.adjacentScreenIndex(i, neighbourDirs[j].x, neighbourDirs[j].y);
         if (idx != -1 && !config.screens()[idx].isNull())
           outStream << "\t\t" << neighbourDirs[j].name << " = " << config.screens()[idx].name() << Qt::endl;
diff --git a/src/lib/net/SecureSocket.cpp b/src/lib/net/SecureSocket.cpp
index 3d85d3db2..57d77533d 100644
--- a/src/lib/net/SecureSocket.cpp
+++ b/src/lib/net/SecureSocket.cpp
@@ -113,12 +113,13 @@ TCPSocket::JobResult SecureSocket::doRead()
 {
   using enum JobResult;
   static uint8_t buffer[4096];
-  memset(buffer, 0, sizeof(buffer));
+  static const auto bufferSize = std::size(buffer);
+  memset(buffer, 0, bufferSize);
   int bytesRead = 0;
   int status = 0;
 
   if (isSecureReady()) {
-    status = secureRead(buffer, sizeof(buffer), bytesRead);
+    status = secureRead(buffer, bufferSize, bytesRead);
     if (status < 0) {
       return Break;
     } else if (status == 0) {
@@ -139,7 +140,7 @@ TCPSocket::JobResult SecureSocket::doRead()
         break;
       }
 
-      status = secureRead(buffer, sizeof(buffer), bytesRead);
+      status = secureRead(buffer, bufferSize, bytesRead);
       if (status < 0) {
         return Break;
       }
diff --git a/src/lib/platform/XWindowsScreen.cpp b/src/lib/platform/XWindowsScreen.cpp
index 0c14be0c6..6f5a4f414 100644
--- a/src/lib/platform/XWindowsScreen.cpp
+++ b/src/lib/platform/XWindowsScreen.cpp
@@ -556,7 +556,7 @@ uint32_t XWindowsScreen::registerHotKey(KeyID key, KeyModifierMask mask)
       };
 
       XModifierKeymap *modKeymap = XGetModifierMapping(m_display);
-      for (size_t j = 0; j < sizeof(s_hotKeyModifiers) / sizeof(s_hotKeyModifiers[0]) && !err; ++j) {
+      for (size_t j = 0; j < std::size(s_hotKeyModifiers) && !err; ++j) {
         // skip modifier if not in mask
         if ((mask & s_hotKeyModifiers[j]) == 0) {
           continue;
@@ -1728,7 +1728,7 @@ KeyID XWindowsScreen::mapKeyFromX(XKeyEvent *event) const
     // do multibyte lookup.  can only call XmbLookupString with a
     // key press event and a valid XIC so we checked those above.
     char scratch[32];
-    int n = sizeof(scratch) / sizeof(scratch[0]);
+    auto n = static_cast<int>(std::size(scratch));
     char *buffer = scratch;
     int status;
     n = XmbLookupString(m_ic, event, buffer, n, &keysym, &status);
diff --git a/src/lib/platform/XWindowsUtil.cpp b/src/lib/platform/XWindowsUtil.cpp
index 606fedfa3..f7d330330 100644
--- a/src/lib/platform/XWindowsUtil.cpp
+++ b/src/lib/platform/XWindowsUtil.cpp
@@ -1885,7 +1885,7 @@ Bool XWindowsUtil::propertyNotifyPredicate(Display *, XEvent *xevent, XPointer a
 void XWindowsUtil::initKeyMaps()
 {
   if (s_keySymToUCS4.empty()) {
-    for (size_t i = 0; i < sizeof(s_keymap) / sizeof(s_keymap[0]); ++i) {
+    for (size_t i = 0; i < std::size(s_keymap); ++i) {
       s_keySymToUCS4[s_keymap[i].keysym] = s_keymap[i].ucs4;
     }
   }