diff --git a/src/main/scala/li/cil/oc/server/fs/Buffered.scala b/src/main/scala/li/cil/oc/server/fs/Buffered.scala
index fd4fbf1b4..c09c83d82 100644
--- a/src/main/scala/li/cil/oc/server/fs/Buffered.scala
+++ b/src/main/scala/li/cil/oc/server/fs/Buffered.scala
@@ -14,6 +14,8 @@ trait Buffered extends OutputStreamFileSystem {
 
   private val deletions = mutable.Map.empty[String, Long]
 
+  protected def isValidFilename(name: String) = true
+
   // ----------------------------------------------------------------------- //
 
   override def delete(path: String) = {
@@ -37,7 +39,7 @@ trait Buffered extends OutputStreamFileSystem {
   override def load(nbt: NBTTagCompound) = {
     def recurse(path: String, directory: io.File) {
       makeDirectory(path)
-      for (child <- directory.listFiles()) {
+      for (child <- directory.listFiles() if isValidFilename(child.getName)) {
         val childPath = path + child.getName
         val childFile = new io.File(directory, child.getName)
         if (child.isDirectory) {
diff --git a/src/main/scala/li/cil/oc/server/fs/FileSystem.scala b/src/main/scala/li/cil/oc/server/fs/FileSystem.scala
index 2c48b6bb2..86422ab36 100644
--- a/src/main/scala/li/cil/oc/server/fs/FileSystem.scala
+++ b/src/main/scala/li/cil/oc/server/fs/FileSystem.scala
@@ -158,6 +158,8 @@ object FileSystem extends api.detail.FileSystemAPI {
     // accordingly before the path is passed to the file system.
     private val invalidChars = """\:*?"<>|""".toSet
 
+    override protected def isValidFilename(name: String) = !name.exists(invalidChars.contains)
+
     override def makeDirectory(path: String) = super.makeDirectory(validatePath(path))
 
     override protected def openOutputHandle(id: Int, path: String, mode: Mode) = super.openOutputHandle(id, validatePath(path), mode)
@@ -168,7 +170,7 @@ object FileSystem extends api.detail.FileSystemAPI {
     }
 
     private def validatePath(path: String) = {
-      if (path.exists(invalidChars.contains)) {
+      if (!isValidFilename(path)) {
         throw new java.io.IOException("path contains invalid characters")
       }
       path