diff --git a/filetypes.xml b/filetypes.xml
index 8a5b9ef..291d081 100644
--- a/filetypes.xml
+++ b/filetypes.xml
@@ -2,6 +2,7 @@
   <component name="FileTypeManager" version="19">
     <extensionMap>
       <mapping ext="csv" type="PLAIN_TEXT" />
+      <mapping ext="stl" type="PLAIN_TEXT" />
       <mapping ext="obj" type="PLAIN_TEXT" />
       <mapping ext="mtl" type="PLAIN_TEXT" />
       <removed_mapping ext="apk" approved="true" type="ARCHIVE" />