diff --git a/Directory.cxx b/Directory.cxx
index ca1cb18b6d95fdc0702a0771d9a315fe5af0812d..5141d451929bc2499fa1e45e046b25063ff479a5 100644
--- a/Directory.cxx
+++ b/Directory.cxx
@@ -109,7 +109,7 @@ bool Directory::Load(const std::string& name)
     // Make sure the slashes in the wildcard suffix are consistent with the
     // rest of the path
     buf = new char[n + 2 + 1];
-    if (name.find('\\') != name.npos) {
+    if (name.find('\\') != std::string::npos) {
       sprintf(buf, "%s\\*", name.c_str());
     } else {
       sprintf(buf, "%s/*", name.c_str());
diff --git a/EncodingCXX.cxx b/EncodingCXX.cxx
index 641c0e6a8e6ad1c5b027431555ec2eab78b4256a..b1e54c958aa1398fce4465baf5e8bdb127b4e557 100644
--- a/EncodingCXX.cxx
+++ b/EncodingCXX.cxx
@@ -147,11 +147,11 @@ std::wstring Encoding::ToWide(const std::string& str)
       wstr += ToWide(str.c_str() + pos);
     }
     nullPos = str.find('\0', pos);
-    if (nullPos != str.npos) {
+    if (nullPos != std::string::npos) {
       pos = nullPos + 1;
       wstr += wchar_t('\0');
     }
-  } while (nullPos != str.npos);
+  } while (nullPos != std::string::npos);
 #endif
   return wstr;
 }
@@ -181,11 +181,11 @@ std::string Encoding::ToNarrow(const std::wstring& str)
       nstr += ToNarrow(str.c_str() + pos);
     }
     nullPos = str.find(wchar_t('\0'), pos);
-    if (nullPos != str.npos) {
+    if (nullPos != std::string::npos) {
       pos = nullPos + 1;
       nstr += '\0';
     }
-  } while (nullPos != str.npos);
+  } while (nullPos != std::string::npos);
 #endif
   return nstr;
 }
diff --git a/SystemInformation.cxx b/SystemInformation.cxx
index bfc895e945cb12699abd11bf20e0593fa77769e2..21fe135a96317bb06adb67decbd002ef417bf578 100644
--- a/SystemInformation.cxx
+++ b/SystemInformation.cxx
@@ -3341,11 +3341,11 @@ std::string SystemInformationImplementation::ExtractValueFromCpuInfoFile(
   std::string buffer, const char* word, size_t init)
 {
   size_t pos = buffer.find(word, init);
-  if (pos != buffer.npos) {
+  if (pos != std::string::npos) {
     this->CurrentPositionInFile = pos;
     pos = buffer.find(":", pos);
     size_t pos2 = buffer.find("\n", pos);
-    if (pos != buffer.npos && pos2 != buffer.npos) {
+    if (pos != std::string::npos && pos2 != std::string::npos) {
       // It may happen that the beginning matches, but this is still not the
       // requested key.
       // An example is looking for "cpu" when "cpu family" comes first. So we
@@ -3360,7 +3360,7 @@ std::string SystemInformationImplementation::ExtractValueFromCpuInfoFile(
       return buffer.substr(pos + 2, pos2 - pos - 2);
     }
   }
-  this->CurrentPositionInFile = buffer.npos;
+  this->CurrentPositionInFile = std::string::npos;
   return "";
 }
 
@@ -3387,7 +3387,7 @@ bool SystemInformationImplementation::RetreiveInformationFromCpuInfoFile()
   // Number of logical CPUs (combination of multiple processors, multi-core
   // and SMT)
   size_t pos = buffer.find("processor\t");
-  while (pos != buffer.npos) {
+  while (pos != std::string::npos) {
     this->NumberOfLogicalCPU++;
     pos = buffer.find("processor\t", pos + 1);
   }
@@ -3396,7 +3396,7 @@ bool SystemInformationImplementation::RetreiveInformationFromCpuInfoFile()
   // Count sockets.
   std::set<int> PhysicalIDs;
   std::string idc = this->ExtractValueFromCpuInfoFile(buffer, "physical id");
-  while (this->CurrentPositionInFile != buffer.npos) {
+  while (this->CurrentPositionInFile != std::string::npos) {
     int id = atoi(idc.c_str());
     PhysicalIDs.insert(id);
     idc = this->ExtractValueFromCpuInfoFile(buffer, "physical id",
@@ -3506,7 +3506,7 @@ bool SystemInformationImplementation::RetreiveInformationFromCpuInfoFile()
       this->ExtractValueFromCpuInfoFile(buffer, cachename[index]);
     if (!cacheSize.empty()) {
       pos = cacheSize.find(" KB");
-      if (pos != cacheSize.npos) {
+      if (pos != std::string::npos) {
         cacheSize = cacheSize.substr(0, pos);
       }
       this->Features.L1CacheSize += atoi(cacheSize.c_str());
@@ -4585,10 +4585,10 @@ std::string SystemInformationImplementation::ExtractValueFromSysCtl(
   const char* word)
 {
   size_t pos = this->SysCtlBuffer.find(word);
-  if (pos != this->SysCtlBuffer.npos) {
+  if (pos != std::string::npos) {
     pos = this->SysCtlBuffer.find(": ", pos);
     size_t pos2 = this->SysCtlBuffer.find("\n", pos);
-    if (pos != this->SysCtlBuffer.npos && pos2 != this->SysCtlBuffer.npos) {
+    if (pos != std::string::npos && pos2 != std::string::npos) {
       return this->SysCtlBuffer.substr(pos + 2, pos2 - pos - 2);
     }
   }
@@ -4660,14 +4660,14 @@ std::string SystemInformationImplementation::ParseValueFromKStat(
   args.push_back("-p");
 
   std::string command = arguments;
-  size_t start = command.npos;
+  size_t start = std::string::npos;
   size_t pos = command.find(' ', 0);
-  while (pos != command.npos) {
+  while (pos != std::string::npos) {
     bool inQuotes = false;
     // Check if we are between quotes
     size_t b0 = command.find('"', 0);
     size_t b1 = command.find('"', b0 + 1);
-    while (b0 != command.npos && b1 != command.npos && b1 > b0) {
+    while (b0 != std::string::npos && b1 != std::string::npos && b1 > b0) {
       if (pos > b0 && pos < b1) {
         inQuotes = true;
         break;
@@ -4681,7 +4681,7 @@ std::string SystemInformationImplementation::ParseValueFromKStat(
 
       // Remove the quotes if any
       size_t quotes = arg.find('"');
-      while (quotes != arg.npos) {
+      while (quotes != std::string::npos) {
         arg.erase(quotes, 1);
         quotes = arg.find('"');
       }
@@ -4864,11 +4864,11 @@ bool SystemInformationImplementation::QueryQNXMemory()
   args.clear();
 
   size_t pos = buffer.find("System RAM:");
-  if (pos == buffer.npos)
+  if (pos == std::string::npos)
     return false;
   pos = buffer.find(":", pos);
   size_t pos2 = buffer.find("M (", pos);
-  if (pos2 == buffer.npos)
+  if (pos2 == std::string::npos)
     return false;
 
   pos++;
@@ -4922,11 +4922,11 @@ bool SystemInformationImplementation::QueryQNXProcessor()
   args.clear();
 
   size_t pos = buffer.find("Processor1:");
-  if (pos == buffer.npos)
+  if (pos == std::string::npos)
     return false;
 
   size_t pos2 = buffer.find("MHz", pos);
-  if (pos2 == buffer.npos)
+  if (pos2 == std::string::npos)
     return false;
 
   size_t pos3 = pos2;
@@ -4936,9 +4936,9 @@ bool SystemInformationImplementation::QueryQNXProcessor()
   this->CPUSpeedInMHz = atoi(buffer.substr(pos3 + 1, pos2 - pos3 - 1).c_str());
 
   pos2 = buffer.find(" Stepping", pos);
-  if (pos2 != buffer.npos) {
+  if (pos2 != std::string::npos) {
     pos2 = buffer.find(" ", pos2 + 1);
-    if (pos2 != buffer.npos && pos2 < pos3) {
+    if (pos2 != std::string::npos && pos2 < pos3) {
       this->ChipID.Revision =
         atoi(buffer.substr(pos2 + 1, pos3 - pos2).c_str());
     }
@@ -4948,7 +4948,7 @@ bool SystemInformationImplementation::QueryQNXProcessor()
   do {
     pos = buffer.find("\nProcessor", pos + 1);
     ++this->NumberOfPhysicalCPU;
-  } while (pos != buffer.npos);
+  } while (pos != std::string::npos);
   this->NumberOfLogicalCPU = 1;
 
   return true;
diff --git a/SystemTools.cxx b/SystemTools.cxx
index 5ca382fb7f428bf305bcc5245d96a55866f04da5..c75dd0860eee9c6034bc3a0bb09312d1d3c9b234 100644
--- a/SystemTools.cxx
+++ b/SystemTools.cxx
@@ -553,7 +553,7 @@ bool SystemTools::HasEnv(const std::string& key)
 static int kwsysUnPutEnv(const std::string& env)
 {
   size_t pos = env.find('=');
-  if (pos != env.npos) {
+  if (pos != std::string::npos) {
     std::string name = env.substr(0, pos);
     unsetenv(name.c_str());
   } else {
@@ -569,7 +569,7 @@ static int kwsysUnPutEnv(const std::string& env)
 {
   int err = 0;
   size_t pos = env.find('=');
-  size_t const len = pos == env.npos ? env.size() : pos;
+  size_t const len = pos == std::string::npos ? env.size() : pos;
   size_t const sz = len + 1;
   char local_buf[256];
   char* buf = sz > sizeof(local_buf) ? (char*)malloc(sz) : local_buf;
@@ -603,7 +603,7 @@ static int kwsysUnPutEnv(std::string const& env)
 {
   std::wstring wEnv = Encoding::ToWide(env);
   size_t const pos = wEnv.find('=');
-  size_t const len = pos == wEnv.npos ? wEnv.size() : pos;
+  size_t const len = pos == std::string::npos ? wEnv.size() : pos;
   wEnv.resize(len + 1, L'=');
   wchar_t* newEnv = _wcsdup(wEnv.c_str());
   if (!newEnv) {
@@ -619,7 +619,7 @@ static int kwsysUnPutEnv(std::string const& env)
 static int kwsysUnPutEnv(const std::string& env)
 {
   size_t pos = env.find('=');
-  size_t const len = pos == env.npos ? env.size() : pos;
+  size_t const len = pos == std::string::npos ? env.size() : pos;
   int in = 0;
   int out = 0;
   while (environ[in]) {
@@ -644,7 +644,7 @@ static int kwsysUnPutEnv(const std::string& env)
 bool SystemTools::PutEnv(const std::string& env)
 {
   size_t pos = env.find('=');
-  if (pos != env.npos) {
+  if (pos != std::string::npos) {
     std::string name = env.substr(0, pos);
     return setenv(name.c_str(), env.c_str() + pos + 1, 1) == 0;
   } else {
@@ -1850,7 +1850,7 @@ static void ConvertVMSToUnix(std::string& path)
 {
   std::string::size_type rootEnd = path.find(":[");
   std::string::size_type pathEnd = path.find("]");
-  if (rootEnd != path.npos) {
+  if (rootEnd != std::string::npos) {
     std::string root = path.substr(0, rootEnd);
     std::string pathPart = path.substr(rootEnd + 2, pathEnd - rootEnd - 2);
     const char* pathCString = pathPart.c_str();
@@ -4326,7 +4326,7 @@ bool SystemTools::GetPermissions(const std::string& file, mode_t& mode)
     mode |= S_IFREG;
   }
   size_t dotPos = file.rfind('.');
-  const char* ext = dotPos == file.npos ? 0 : (file.c_str() + dotPos);
+  const char* ext = dotPos == std::string::npos ? 0 : (file.c_str() + dotPos);
   if (ext && (Strucmp(ext, ".exe") == 0 || Strucmp(ext, ".com") == 0 ||
               Strucmp(ext, ".cmd") == 0 || Strucmp(ext, ".bat") == 0)) {
     mode |= (_S_IEXEC | (_S_IEXEC >> 3) | (_S_IEXEC >> 6));
diff --git a/testConsoleBuf.cxx b/testConsoleBuf.cxx
index 21930f9ba65d81c5fef2cb1c412f1ee6acb0dd93..816a4338e69a941a343d1f330070a581d4630436 100644
--- a/testConsoleBuf.cxx
+++ b/testConsoleBuf.cxx
@@ -329,9 +329,8 @@ static int testPipe()
             throw std::runtime_error("ReadFile#3 failed!");
           }
           buffer2[bytesRead] = 0;
-          didFail =
-            encodedTestString.compare(0, encodedTestString.npos, buffer2,
-                                      encodedTestString.size()) == 0
+          didFail = encodedTestString.compare(0, std::string::npos, buffer2,
+                                              encodedTestString.size()) == 0
             ? 0
             : 1;
         }
@@ -435,9 +434,8 @@ static int testFile()
             throw std::runtime_error("ReadFile#2 failed!");
           }
           buffer2[bytesRead] = 0;
-          didFail =
-            encodedTestString.compare(0, encodedTestString.npos, buffer2,
-                                      encodedTestString.size()) == 0
+          didFail = encodedTestString.compare(0, std::string::npos, buffer2,
+                                              encodedTestString.size()) == 0
             ? 0
             : 1;
         }