diff --git a/src/common/filesystembase.cpp b/src/common/filesystembase.cpp
index 8bbca4922c..5eb9dbd298 100644
--- a/src/common/filesystembase.cpp
+++ b/src/common/filesystembase.cpp
@@ -205,14 +205,8 @@ bool FileSystem::uncheckedRenameReplace(const QString &originFileName,
         (wchar_t *)dest.utf16(),
         MOVEFILE_REPLACE_EXISTING + MOVEFILE_COPY_ALLOWED + MOVEFILE_WRITE_THROUGH);
     if (!ok) {
-        wchar_t *string = 0;
-        FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM,
-            nullptr, ::GetLastError(), MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
-            (LPWSTR)&string, 0, nullptr);
-
-        *errorString = QString::fromWCharArray(string);
+        *errorString = Utility::formatWinError(GetLastError());
         qCWarning(lcFileSystem) << "Renaming temp file to final failed: " << *errorString;
-        LocalFree((HLOCAL)string);
         return false;
     }
 #endif
@@ -449,13 +443,13 @@ bool FileSystem::moveToTrash(const QString &fileName, QString *errorString)
 bool FileSystem::isFileLocked(const QString &fileName)
 {
 #ifdef Q_OS_WIN
-    const wchar_t *wuri = reinterpret_cast<const wchar_t *>(fileName.utf16());
     // Check if file exists
-    DWORD attr = GetFileAttributesW(wuri);
+    const QString fName = longWinPath(fileName);
+    DWORD attr = GetFileAttributesW(reinterpret_cast<const wchar_t *>(fName.utf16()));
     if (attr != INVALID_FILE_ATTRIBUTES) {
         // Try to open the file with as much access as possible..
         HANDLE win_h = CreateFileW(
-            wuri,
+            reinterpret_cast<const wchar_t *>(fName.utf16()),
             GENERIC_READ | GENERIC_WRITE,
             FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
             nullptr, OPEN_EXISTING,
@@ -493,7 +487,7 @@ bool FileSystem::isJunction(const QString &filename)
 {
 #ifdef Q_OS_WIN
     WIN32_FIND_DATA findData;
-    HANDLE hFind = FindFirstFileEx((const wchar_t *)filename.utf16(), FindExInfoBasic, &findData, FindExSearchNameMatch, nullptr, 0);
+    HANDLE hFind = FindFirstFileEx(reinterpret_cast<const wchar_t *>(longWinPath(filename).utf16()), FindExInfoBasic, &findData, FindExSearchNameMatch, nullptr, 0);
     if (hFind != INVALID_HANDLE_VALUE) {
         FindClose(hFind);
         return false;
diff --git a/src/common/utility.cpp b/src/common/utility.cpp
index c9b0a81fd8..e31534ca38 100644
--- a/src/common/utility.cpp
+++ b/src/common/utility.cpp
@@ -19,6 +19,7 @@
 #include "config.h"
 
 #include "common/utility.h"
+#include "common/filesystembase.h"
 #include "version.h"
 
 // Note:  This file must compile without QtGui
@@ -229,7 +230,7 @@ qint64 Utility::freeDiskSpace(const QString &path)
 #elif defined(Q_OS_WIN)
     ULARGE_INTEGER freeBytes;
     freeBytes.QuadPart = 0L;
-    if (GetDiskFreeSpaceEx(reinterpret_cast<const wchar_t *>(path.utf16()), &freeBytes, nullptr, nullptr)) {
+    if (GetDiskFreeSpaceEx(reinterpret_cast<const wchar_t *>(FileSystem::longWinPath(path).utf16()), &freeBytes, nullptr, nullptr)) {
         return freeBytes.QuadPart;
     }
 #endif
diff --git a/src/libsync/owncloudpropagator.cpp b/src/libsync/owncloudpropagator.cpp
index 4c35a3956f..dcc5dc7d6c 100644
--- a/src/libsync/owncloudpropagator.cpp
+++ b/src/libsync/owncloudpropagator.cpp
@@ -548,7 +548,7 @@ bool OwncloudPropagator::localFileNameClash(const QString &relFile)
         WIN32_FIND_DATA FindFileData;
         HANDLE hFind;
 
-        hFind = FindFirstFileW((wchar_t *)file.utf16(), &FindFileData);
+        hFind = FindFirstFileW(reinterpret_cast<const wchar_t *>(FileSystem::longWinPath(file).utf16()), &FindFileData);
         if (hFind == INVALID_HANDLE_VALUE) {
             // returns false.
         } else {
@@ -582,7 +582,7 @@ bool OwncloudPropagator::hasCaseClashAccessibilityProblem(const QString &relfile
     WIN32_FIND_DATA FindFileData;
     HANDLE hFind;
 
-    hFind = FindFirstFileW(reinterpret_cast<const wchar_t *>(file.utf16()), &FindFileData);
+    hFind = FindFirstFileW(reinterpret_cast<const wchar_t *>(FileSystem::longWinPath(file).utf16()), &FindFileData);
     if (hFind != INVALID_HANDLE_VALUE) {
         QString firstFile = QString::fromWCharArray(FindFileData.cFileName);
         if (FindNextFile(hFind, &FindFileData)) {