diff --git a/polymod/Polymod.hx b/polymod/Polymod.hx
index ac8a4817..26f41023 100644
--- a/polymod/Polymod.hx
+++ b/polymod/Polymod.hx
@@ -918,6 +918,11 @@ class ModMetadata
    */
   public var modPath:String;
 
+  /**
+   * The directory name of the mod.
+   */
+  public var dirName:String;
+
   /**
    * `metadata` provides an optional list of keys.
    * These can provide additional information about the mod, specific to your application.
@@ -1021,6 +1026,7 @@ class ModMetadata
     }
 
     var m = new ModMetadata();
+    m.id = JsonHelp.str(json, 'id');
     m.title = JsonHelp.str(json, 'title');
     m.description = JsonHelp.str(json, 'description');
     m._author = JsonHelp.str(json, 'author');
diff --git a/polymod/fs/MemoryFileSystem.hx b/polymod/fs/MemoryFileSystem.hx
index b445a8ff..efcc7429 100644
--- a/polymod/fs/MemoryFileSystem.hx
+++ b/polymod/fs/MemoryFileSystem.hx
@@ -188,9 +188,9 @@ class MemoryFileSystem implements PolymodFileSystem.IFileSystem
     return result;
   }
 
-  public function getMetadata(modId:String)
+  public function getMetadata(dirName:String)
   {
-    var modpath = Util.pathJoin(modRoot, modId);
+    var modpath = Util.pathJoin(modRoot, dirName);
     if (exists(modpath))
     {
       var meta:ModMetadata = null;
@@ -209,7 +209,8 @@ class MemoryFileSystem implements PolymodFileSystem.IFileSystem
         meta = ModMetadata.fromJsonStr(metaText);
         if (meta == null) return null;
 
-        meta.id = modId;
+        meta.id = meta.id == '' ? dirName : meta.id;
+        meta.dirName = dirName;
         meta.modPath = modpath;
       }
 
@@ -227,7 +228,7 @@ class MemoryFileSystem implements PolymodFileSystem.IFileSystem
     }
     else
     {
-      Polymod.error(MISSING_MOD, 'Could not find mod directory: $modpath');
+      Polymod.error(MISSING_MOD, 'Could not find mod directory: $dirName');
     }
     return null;
   }
diff --git a/polymod/fs/SysFileSystem.hx b/polymod/fs/SysFileSystem.hx
index 47c15641..5fb13523 100644
--- a/polymod/fs/SysFileSystem.hx
+++ b/polymod/fs/SysFileSystem.hx
@@ -104,9 +104,9 @@ class SysFileSystem implements IFileSystem
     return result;
   }
 
-  public function getMetadata(modId:String)
+  public function getMetadata(dirName:String)
   {
-    var modPath = Util.pathJoin(modRoot, modId);
+    var modPath = Util.pathJoin(modRoot, dirName);
     if (exists(modPath))
     {
       var meta:ModMetadata = null;
@@ -127,7 +127,8 @@ class SysFileSystem implements IFileSystem
 
       if (meta == null) return null;
 
-      meta.id = modId;
+      meta.id = meta.id == '' ? dirName : meta.id;
+      meta.dirName = dirName;
       meta.modPath = modPath;
 
       if (!exists(iconFile))
@@ -144,7 +145,7 @@ class SysFileSystem implements IFileSystem
     }
     else
     {
-      Polymod.error(MISSING_MOD, 'Could not find mod directory: $modId');
+      Polymod.error(MISSING_MOD, 'Could not find mod directory: $dirName');
     }
     return null;
   }