diff --git a/common/lc_global.h b/common/lc_global.h
index 399035b0..a23fc617 100644
--- a/common/lc_global.h
+++ b/common/lc_global.h
@@ -46,7 +46,6 @@
 char* strcasestr(const char *s, const char *find);
 #else
 char* strupr(char* string);
-char* strlwr(char* string);
 #endif
 
 // Version number.
diff --git a/common/lc_library.cpp b/common/lc_library.cpp
index 03bd60e4..bd1ebf49 100644
--- a/common/lc_library.cpp
+++ b/common/lc_library.cpp
@@ -1352,18 +1352,16 @@ void lcPiecesLibrary::GetPieceFile(const char* PieceName, std::function<void(lcF
 		{
 			lcDiskFile IncludeFile;
 
-			auto LoadIncludeFile = [&IncludeFile, PieceName, this](const char* Folder)
+			auto LoadIncludeFile = [&IncludeFile, PieceName, this](const QLatin1String& Folder)
 			{
-				char IncludeFileName[LC_MAXPATH];
-				sprintf(IncludeFileName, Folder, PieceName);
-				IncludeFile.SetFileName(mLibraryDir.absoluteFilePath(QLatin1String(IncludeFileName)));
+				const QString IncludeFileName = Folder + PieceName;
+				IncludeFile.SetFileName(mLibraryDir.absoluteFilePath(IncludeFileName));
 				if (IncludeFile.Open(QIODevice::ReadOnly))
 					return true;
 
 #if defined(Q_OS_MACOS) || defined(Q_OS_LINUX)
-				// todo: instead of using strlwr, search the parts/primitive lists and get the file name from there
-				strlwr(IncludeFileName);
-				IncludeFile.SetFileName(mLibraryDir.absoluteFilePath(QLatin1String(IncludeFileName)));
+				// todo: search the parts/primitive lists and get the file name from there instead of using toLower
+				IncludeFile.SetFileName(mLibraryDir.absoluteFilePath(IncludeFileName.toLower()));
 				return IncludeFile.Open(QIODevice::ReadOnly);
 #else
 				return false;
@@ -1372,18 +1370,18 @@ void lcPiecesLibrary::GetPieceFile(const char* PieceName, std::function<void(lcF
 
 			if (mHasUnofficial)
 			{
-				Found = LoadIncludeFile("unofficial/parts/%s");
+				Found = LoadIncludeFile(QLatin1String("unofficial/parts/"));
 
 				if (!Found)
-					Found = LoadIncludeFile("unofficial/p/%s");
+					Found = LoadIncludeFile(QLatin1String("unofficial/p/"));
 			}
 
 			if (!Found)
 			{
-				Found = LoadIncludeFile("parts/%s");
+				Found = LoadIncludeFile(QLatin1String("parts/"));
 
 				if (!Found)
-					Found = LoadIncludeFile("p/%s");
+					Found = LoadIncludeFile(QLatin1String("p/"));
 			}
 
 			if (Found)
diff --git a/qt/system.cpp b/qt/system.cpp
index b4a5a3c0..36d636d9 100644
--- a/qt/system.cpp
+++ b/qt/system.cpp
@@ -1,6 +1,6 @@
 #include "lc_global.h"
 
-#ifdef WIN32
+#ifdef Q_OS_WIN
 
 char* strcasestr(const char *s, const char *find)
 {
@@ -33,12 +33,4 @@ char* strupr(char *string)
 	return string;
 }
 
-char* strlwr(char *string)
-{
-	for (char *c = string; *c; c++)
-		*c = tolower(*c);
-
-	return string;
-}
-
 #endif