diff --git a/src/cpp/eMailShrinker.cpp b/src/cpp/eMailShrinker.cpp
index 5a5bdf3..03ea6b0 100644
--- a/src/cpp/eMailShrinker.cpp
+++ b/src/cpp/eMailShrinker.cpp
@@ -193,10 +193,10 @@ main (int argc, char** argv) {
   MainAttachment attachment (mbox);
   mbox.close ();
 
-  // if (attachment.getBoundary ().empty ()) {
-  //   cerr << "no attachment" << endl;
-  //   return 1;
-  // }
+  if (attachment.getBoundary ().empty ()) {
+    cerr << "no attachment" << endl;
+    return 1;
+  }
   // parse structure
   mbox.open (inputName);
   attachment.markSignificant (minAttachSize, mbox);