diff --git a/aegisub/src/dialog_attachments.cpp b/aegisub/src/dialog_attachments.cpp
index 390cb84f8..2300f30ed 100644
--- a/aegisub/src/dialog_attachments.cpp
+++ b/aegisub/src/dialog_attachments.cpp
@@ -176,6 +176,8 @@ void DialogAttachments::OnAttachFont(wxCommandEvent &event) {
 		AssFile::top->InsertAttachment(newAttach);
 	}
 
+	AssFile::top->FlagAsModified(_("attach font file"));
+
 	// Update
 	UpdateList();
 }
@@ -212,6 +214,8 @@ void DialogAttachments::OnAttachGraphics(wxCommandEvent &event) {
 		AssFile::top->InsertAttachment(newAttach);
 	}
 
+	AssFile::top->FlagAsModified(_("attach graphics file"));
+
 	// Update
 	UpdateList();
 }
@@ -265,6 +269,8 @@ void DialogAttachments::OnDelete(wxCommandEvent &event) {
 		i = listView->GetNextSelected(i);
 	}
 
+	AssFile::top->FlagAsModified(_("remove attachment"));
+
 	// Update list
 	UpdateList();
 }