diff --git a/src/common/Stack.hxx b/src/common/Stack.hxx
index a08e55d59..8eb48e4f6 100644
--- a/src/common/Stack.hxx
+++ b/src/common/Stack.hxx
@@ -43,7 +43,7 @@ class FixedStack
     bool full() const  { return _size >= CAPACITY; }
 
     T top() const { return _stack[_size - 1];    }
-    T get(uInt32 pos) { return _stack[pos]; }
+    T get(uInt32 pos) const { return _stack[pos]; }
     void push(const T& x) { _stack[_size++] = x; }
     T pop() { return std::move(_stack[--_size]); }
     uInt32 size() const { return _size; }
diff --git a/src/emucore/OSystem.cxx b/src/emucore/OSystem.cxx
index c1159982e..d2c9606d6 100644
--- a/src/emucore/OSystem.cxx
+++ b/src/emucore/OSystem.cxx
@@ -782,14 +782,17 @@ string OSystem::getROMMD5(const FilesystemNode& rom) const
 ByteBuffer OSystem::openROM(const FilesystemNode& rom, size_t& size,
                             bool showErrorMessage) const
 {
-  // First check if this is a 'streaming' ROM (one where we only read
-  // a portion of the file)
+  // First check if this is a valid ROM filename
+  const bool isValidROM = rom.isFile() && Bankswitch::isValidRomName(rom);
+  if(!isValidROM && showErrorMessage)
+    throw runtime_error("Unrecognized ROM file type");
+
+  // Next check for a proper file size:
+  //   Streaming ROMs read only a portion of the file
+  //   TODO: Otherwise, cap the size to the maximum Cart size
   const size_t sizeToRead = CartDetector::isProbablyMVC(rom);
 
-  // Next check if rom is a valid size
-  // TODO: We should check if ROM is < Cart::maxSize(), but only
-  //       if it's not a ZIP file (that size should be higher; still TBD)
-
+  // Now we can try to open the file
   ByteBuffer image;
   try
   {
diff --git a/src/gui/FileListWidget.cxx b/src/gui/FileListWidget.cxx
index 9c8d831cb..8ad16a624 100644
--- a/src/gui/FileListWidget.cxx
+++ b/src/gui/FileListWidget.cxx
@@ -166,7 +166,7 @@ FileListWidget::IconType FileListWidget::getIconType(const string& path) const
       ? IconType::zip : IconType::directory;
   }
   else
-    return node.isFile() && Bankswitch::isValidRomName(node.getName())
+    return node.isFile() && Bankswitch::isValidRomName(node)
       ? IconType::rom : IconType::unknown;
 }