diff --git a/PowerEditor/src/MISC/Common/Common.cpp b/PowerEditor/src/MISC/Common/Common.cpp
index eaacb312..ecb972c1 100644
--- a/PowerEditor/src/MISC/Common/Common.cpp
+++ b/PowerEditor/src/MISC/Common/Common.cpp
@@ -29,6 +29,7 @@
 #include <shlwapi.h>
 #include <shlobj.h>
 #include <uxtheme.h>
+#include <cassert>
 #include "StaticDialog.h"
 
 #include "Common.h"
@@ -850,6 +851,64 @@ double stodLocale(const generic_string& str, _locale_t loc, size_t* idx)
 	return ans;
 }
 
+// Source: https://blogs.msdn.microsoft.com/greggm/2005/09/21/comparing-file-names-in-native-code/
+// Modified to use TCHAR's instead of assuming Unicode and reformatted to conform with Notepad++ code style
+static TCHAR ToUpperInvariant(TCHAR input)
+{
+	TCHAR result;
+	LONG lres = LCMapString(LOCALE_INVARIANT, LCMAP_UPPERCASE, &input, 1, &result, 1);
+	if (lres == 0)
+	{
+		assert(false and "LCMapString failed to convert a character to upper case");
+		result = input;
+	}
+	return result;
+}
+
+// Source: https://blogs.msdn.microsoft.com/greggm/2005/09/21/comparing-file-names-in-native-code/
+// Modified to use TCHAR's instead of assuming Unicode and reformatted to conform with Notepad++ code style
+int OrdinalIgnoreCaseCompareStrings(LPCTSTR sz1, LPCTSTR sz2)
+{
+	if (sz1 == sz2)
+	{
+		return 0;
+	}
+
+	if (sz1 == nullptr) sz1 = _T("");
+	if (sz2 == nullptr) sz2 = _T("");
+
+	for (;; sz1++, sz2++)
+	{
+		const TCHAR c1 = *sz1;
+		const TCHAR c2 = *sz2;
+
+		// check for binary equality first
+		if (c1 == c2)
+		{
+			if (c1 == 0)
+			{
+				return 0; // We have reached the end of both strings. No difference found.
+			}
+		}
+		else
+		{
+			if (c1 == 0 || c2 == 0)
+			{
+				return (c1-c2); // We have reached the end of one string
+			}
+
+			// IMPORTANT: this needs to be upper case to match the behavior of the operating system.
+			// See http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dndotnet/html/StringsinNET20.asp
+			const TCHAR u1 = ToUpperInvariant(c1);
+			const TCHAR u2 = ToUpperInvariant(c2);
+			if (u1 != u2)
+			{
+				return (u1-u2); // strings are different
+			}
+		}
+	}
+}
+
 bool str2Clipboard(const generic_string &str2cpy, HWND hwnd)
 {
 	size_t len2Allocate = (str2cpy.size() + 1) * sizeof(TCHAR);
diff --git a/PowerEditor/src/MISC/Common/Common.h b/PowerEditor/src/MISC/Common/Common.h
index 20a76581..3d652293 100644
--- a/PowerEditor/src/MISC/Common/Common.h
+++ b/PowerEditor/src/MISC/Common/Common.h
@@ -178,6 +178,8 @@ generic_string stringJoin(const std::vector<generic_string>& strings, const gene
 generic_string stringTakeWhileAdmissable(const generic_string& input, const generic_string& admissable);
 double stodLocale(const generic_string& str, _locale_t loc, size_t* idx = NULL);
 
+int OrdinalIgnoreCaseCompareStrings(LPCTSTR sz1, LPCTSTR sz2);
+
 bool str2Clipboard(const generic_string &str2cpy, HWND hwnd);
 
 generic_string GetLastErrorAsString(DWORD errorCode = 0);
diff --git a/PowerEditor/src/Notepad_plus.cpp b/PowerEditor/src/Notepad_plus.cpp
index b69cb41e..a9a13d0f 100644
--- a/PowerEditor/src/Notepad_plus.cpp
+++ b/PowerEditor/src/Notepad_plus.cpp
@@ -1409,7 +1409,7 @@ void Notepad_plus::getMatchedFileNames(const TCHAR *dir, const vector<generic_st
 			}
 			else if (isRecursive)
 			{
-				if ((lstrcmp(foundData.cFileName, TEXT("."))) && (lstrcmp(foundData.cFileName, TEXT(".."))))
+				if ((OrdinalIgnoreCaseCompareStrings(foundData.cFileName, TEXT(".")) != 0) && (OrdinalIgnoreCaseCompareStrings(foundData.cFileName, TEXT("..")) != 0))
 				{
 					generic_string pathDir(dir);
 					pathDir += foundData.cFileName;
@@ -1438,7 +1438,7 @@ void Notepad_plus::getMatchedFileNames(const TCHAR *dir, const vector<generic_st
 			}
 			else if (isRecursive)
 			{
-				if ((lstrcmp(foundData.cFileName, TEXT("."))) && (lstrcmp(foundData.cFileName, TEXT(".."))))
+				if ((OrdinalIgnoreCaseCompareStrings(foundData.cFileName, TEXT(".")) != 0) && (OrdinalIgnoreCaseCompareStrings(foundData.cFileName, TEXT("..")) != 0))
 				{
 					generic_string pathDir(dir);
 					pathDir += foundData.cFileName;
diff --git a/PowerEditor/src/NppIO.cpp b/PowerEditor/src/NppIO.cpp
index a1c22704..cc5c1c73 100644
--- a/PowerEditor/src/NppIO.cpp
+++ b/PowerEditor/src/NppIO.cpp
@@ -95,7 +95,7 @@ DWORD WINAPI Notepad_plus::monitorFileOnChange(void * params)
 					if (pos == 2)
 						fn.replace(pos, 2, TEXT("\\"));
 
-					if (lstrcmp(fullFileName, fn.c_str()) == 0)
+					if (OrdinalIgnoreCaseCompareStrings(fullFileName, fn.c_str()) == 0)
 					{
 						if (dwAction == FILE_ACTION_MODIFIED)
 						{
diff --git a/PowerEditor/src/ScitillaComponent/Buffer.cpp b/PowerEditor/src/ScitillaComponent/Buffer.cpp
index c322c0be..70d1b2cd 100644
--- a/PowerEditor/src/ScitillaComponent/Buffer.cpp
+++ b/PowerEditor/src/ScitillaComponent/Buffer.cpp
@@ -194,13 +194,13 @@ void Buffer::setFileName(const TCHAR *fn, LangType defaultLang)
 
 	if (newLang == defaultLang || newLang == L_TEXT)	//language can probably be refined
 	{
-		if ((!generic_stricmp(_fileName, TEXT("makefile"))) || (!generic_stricmp(_fileName, TEXT("GNUmakefile"))))
+		if ((OrdinalIgnoreCaseCompareStrings(_fileName, TEXT("makefile")) == 0) || (OrdinalIgnoreCaseCompareStrings(_fileName, TEXT("GNUmakefile")) == 0))
 			newLang = L_MAKEFILE;
-		else if (!generic_stricmp(_fileName, TEXT("CmakeLists.txt")))
+		else if (OrdinalIgnoreCaseCompareStrings(_fileName, TEXT("CmakeLists.txt")) == 0)
 			newLang = L_CMAKE;
-		else if ((!generic_stricmp(_fileName, TEXT("SConstruct"))) || (!generic_stricmp(_fileName, TEXT("SConscript"))) || (!generic_stricmp(_fileName, TEXT("wscript"))))
+		else if ((OrdinalIgnoreCaseCompareStrings(_fileName, TEXT("SConstruct")) == 0) || (OrdinalIgnoreCaseCompareStrings(_fileName, TEXT("SConscript")) == 0) || (OrdinalIgnoreCaseCompareStrings(_fileName, TEXT("wscript")) == 0))
 			newLang = L_PYTHON;
-		else if ((!generic_stricmp(_fileName, TEXT("Rakefile"))) || (!generic_stricmp(_fileName, TEXT("Vagrantfile"))))
+		else if ((OrdinalIgnoreCaseCompareStrings(_fileName, TEXT("Rakefile")) == 0) || (OrdinalIgnoreCaseCompareStrings(_fileName, TEXT("Vagrantfile")) == 0))
 			newLang = L_RUBY;
 	}
 
@@ -1507,7 +1507,7 @@ BufferID FileManager::getBufferFromName(const TCHAR* name)
 
 	for(size_t i = 0; i < _buffers.size(); i++)
 	{
-		if (!lstrcmpi(name, _buffers.at(i)->getFullPathName()))
+		if (OrdinalIgnoreCaseCompareStrings(name, _buffers.at(i)->getFullPathName()) == 0)
 			return _buffers.at(i)->getID();
 	}
 	return BUFFER_INVALID;
diff --git a/PowerEditor/src/ScitillaComponent/DocTabView.cpp b/PowerEditor/src/ScitillaComponent/DocTabView.cpp
index 47f77ed3..437b4c64 100644
--- a/PowerEditor/src/ScitillaComponent/DocTabView.cpp
+++ b/PowerEditor/src/ScitillaComponent/DocTabView.cpp
@@ -96,7 +96,7 @@ BufferID DocTabView::findBufferByName(const TCHAR * fullfilename) //-1 if not fo
 		::SendMessage(_hSelf, TCM_GETITEM, i, reinterpret_cast<LPARAM>(&tie));
 		BufferID id = reinterpret_cast<BufferID>(tie.lParam);
 		Buffer * buf = MainFileManager->getBufferByID(id);
-		if (!lstrcmp(fullfilename, buf->getFullPathName()))
+		if (OrdinalIgnoreCaseCompareStrings(fullfilename, buf->getFullPathName()) == 0)
 		{
 			return id;
 		}
diff --git a/PowerEditor/src/WinControls/FileBrowser/fileBrowser.cpp b/PowerEditor/src/WinControls/FileBrowser/fileBrowser.cpp
index 50e96f44..e91c1dc6 100644
--- a/PowerEditor/src/WinControls/FileBrowser/fileBrowser.cpp
+++ b/PowerEditor/src/WinControls/FileBrowser/fileBrowser.cpp
@@ -815,7 +815,7 @@ void FileBrowser::getDirectoryStructure(const TCHAR *dir, const std::vector<gene
 			}
 			else if (isRecursive)
 			{
-				if ((lstrcmp(foundData.cFileName, TEXT("."))) && (lstrcmp(foundData.cFileName, TEXT(".."))))
+				if ((OrdinalIgnoreCaseCompareStrings(foundData.cFileName, TEXT(".")) != 0) && (OrdinalIgnoreCaseCompareStrings(foundData.cFileName, TEXT("..")) != 0))
 				{
 					generic_string pathDir(dir);
 					if (pathDir[pathDir.length() - 1] != '\\')
@@ -848,7 +848,7 @@ void FileBrowser::getDirectoryStructure(const TCHAR *dir, const std::vector<gene
 			}
 			else if (isRecursive)
 			{
-				if ((lstrcmp(foundData.cFileName, TEXT("."))) && (lstrcmp(foundData.cFileName, TEXT(".."))))
+				if ((OrdinalIgnoreCaseCompareStrings(foundData.cFileName, TEXT(".")) != 0) && (OrdinalIgnoreCaseCompareStrings(foundData.cFileName, TEXT("..")) != 0))
 				{
 					generic_string pathDir(dir);
 					if (pathDir[pathDir.length() - 1] != '\\')
diff --git a/PowerEditor/src/WinControls/ProjectPanel/ProjectPanel.cpp b/PowerEditor/src/WinControls/ProjectPanel/ProjectPanel.cpp
index eef62a99..e056a076 100644
--- a/PowerEditor/src/WinControls/ProjectPanel/ProjectPanel.cpp
+++ b/PowerEditor/src/WinControls/ProjectPanel/ProjectPanel.cpp
@@ -1129,7 +1129,7 @@ void ProjectPanel::recursiveAddFilesFrom(const TCHAR *folderPath, HTREEITEM hTre
 			}
 			else if (isRecursive)
 			{
-				if ((lstrcmp(foundData.cFileName, TEXT("."))) && (lstrcmp(foundData.cFileName, TEXT(".."))))
+				if ((OrdinalIgnoreCaseCompareStrings(foundData.cFileName, TEXT(".")) != 0) && (OrdinalIgnoreCaseCompareStrings(foundData.cFileName, TEXT("..")) != 0))
 				{
 					generic_string pathDir(folderPath);
 					if (folderPath[lstrlen(folderPath)-1] != '\\')
diff --git a/PowerEditor/src/lastRecentFileList.cpp b/PowerEditor/src/lastRecentFileList.cpp
index a4a91def..a2687abe 100644
--- a/PowerEditor/src/lastRecentFileList.cpp
+++ b/PowerEditor/src/lastRecentFileList.cpp
@@ -284,7 +284,7 @@ int LastRecentFileList::find(const TCHAR *fn)
 {
 	for(int i = 0; i < _size; ++i)
 	{
-		if (!lstrcmpi(_lrfl.at(i)._name.c_str(), fn))
+		if (OrdinalIgnoreCaseCompareStrings(_lrfl.at(i)._name.c_str(), fn) == 0)
 		{
 			return i;
 		}