diff --git a/IkiWiki/Plugin/attachment.pm b/IkiWiki/Plugin/attachment.pm
index b6327f0c5..bd21ed1ed 100644
--- a/IkiWiki/Plugin/attachment.pm
+++ b/IkiWiki/Plugin/attachment.pm
@@ -143,6 +143,9 @@ sub formbuilder_setup (@) { #{{{
 				IkiWiki::userinfo_set($user_name, "allowed_attachments",
 				$form->field("allowed_attachments")) ||
 					error("failed to set allowed_attachments");
+				if (length $form->field("allowed_attachments")) {
+					$form->field(name => "allowed_attachments", type => "hidden");
+				}
 			}
 		}
 	}
diff --git a/IkiWiki/Plugin/lockedit.pm b/IkiWiki/Plugin/lockedit.pm
index 033b38263..4e1b4f878 100644
--- a/IkiWiki/Plugin/lockedit.pm
+++ b/IkiWiki/Plugin/lockedit.pm
@@ -94,6 +94,9 @@ sub formbuilder_setup (@) { #{{{
 				IkiWiki::userinfo_set($user_name, "locked_pages",
 					$form->field("locked_pages")) ||
 						error("failed to set locked_pages");
+				if (! length $form->field("locked_pages")) {
+					$form->field(name => "locked_pages", type => "hidden");
+				}
 			}
 		}
 	}