diff --git a/src/common/filesystembase.cpp b/src/common/filesystembase.cpp
index 06152e0fbc..88b1c54e2f 100644
--- a/src/common/filesystembase.cpp
+++ b/src/common/filesystembase.cpp
@@ -323,6 +323,25 @@ bool FileSystem::openAndSeekFileSharedRead(QFile *file, QString *errorOrNull, qi
 #endif
 }
 
+QString FileSystem::joinPath(const QString& path, const QString& file)
+{
+    if (path.isEmpty()) {
+        qCWarning(lcFileSystem).nospace() << "joinPath called with an empty path; returning file=" << file;
+        return QDir::toNativeSeparators(file);
+    }
+
+    if (file.isEmpty()) {
+        qCWarning(lcFileSystem).nospace() << "joinPath called with an empty file; returning path=" << path;
+        return QDir::toNativeSeparators(path);
+    }
+
+    if (const auto lastChar = path[path.size() - 1]; lastChar == QLatin1Char{'/'} || lastChar == QLatin1Char{'\\'}) {
+        return QDir::toNativeSeparators(path + file);
+    }
+
+    return QDir::toNativeSeparators(path + QDir::separator() + file);
+}
+
 #ifdef Q_OS_WIN
 std::filesystem::perms FileSystem::filePermissionsWinSymlinkSafe(const QString &filename)
 {
@@ -804,7 +823,7 @@ bool FileSystem::setAclPermission(const QString &unsafePath, FolderPermissions p
         const auto currentFolder = safePathFileInfo.dir();
         const auto childFiles = currentFolder.entryList(QDir::Filter::Files);
         for (const auto &oneEntry : childFiles) {
-            const auto childFile = QDir::toNativeSeparators(path + QDir::separator() + oneEntry);
+            const auto childFile = joinPath(path, oneEntry);
 
             const auto &childFileStdWString = childFile.toStdWString();
             const auto attributes = GetFileAttributes(childFileStdWString.c_str());
diff --git a/src/common/filesystembase.h b/src/common/filesystembase.h
index d88bfd6107..9e115b6c9d 100644
--- a/src/common/filesystembase.h
+++ b/src/common/filesystembase.h
@@ -142,6 +142,16 @@ namespace FileSystem {
      */
     bool OCSYNC_EXPORT openAndSeekFileSharedRead(QFile *file, QString *error, qint64 seek);
 
+    /**
+     * Returns `path + "/" + file` with native directory separators.
+     * 
+     * If `path` ends in a directory separator this method will not insert another one in-between.
+     *
+     * In the case one of the parameters is empty, the other parameter will be returned with native
+     * directory separators and a warning is logged.
+     */
+    QString OCSYNC_EXPORT joinPath(const QString &path, const QString &file);
+
 #ifdef Q_OS_WIN
     /**
      * Returns the file system used at the given path.
diff --git a/src/libsync/filesystem.cpp b/src/libsync/filesystem.cpp
index d2c007ca90..e54ed50033 100644
--- a/src/libsync/filesystem.cpp
+++ b/src/libsync/filesystem.cpp
@@ -265,7 +265,7 @@ bool FileSystem::removeRecursively(const QString &path, const std::function<void
         // we never want to go into this branch for .lnk files
         bool isDir = FileSystem::isDir(fi.absoluteFilePath()) && !FileSystem::isSymLink(fi.absoluteFilePath()) && !FileSystem::isJunction(fi.absoluteFilePath());
         if (isDir) {
-            removeOk = removeRecursively(path + QLatin1Char('/') + di.fileName(), onDeleted, errors, onError); // recursive
+            removeOk = removeRecursively(joinPath(path, di.fileName()), onDeleted, errors, onError); // recursive
         } else {
             QString removeError;