diff --git a/web/modals/threads/thread-settings-modal.react.js b/web/modals/threads/thread-settings-modal.react.js
--- a/web/modals/threads/thread-settings-modal.react.js
+++ b/web/modals/threads/thread-settings-modal.react.js
@@ -114,30 +114,6 @@
     super(props);
   }
 
-  componentDidMount() {
-    invariant(this.nameInput, 'nameInput ref unset');
-    this.nameInput.focus();
-  }
-
-  componentDidUpdate(prevProps: Props) {
-    if (this.props.currentTabType !== 'delete') {
-      return;
-    }
-
-    const permissionForDeleteTab = this.props.hasPermissionForTab(
-      this.props.threadInfo,
-      'delete',
-    );
-    const prevPermissionForDeleteTab = this.props.hasPermissionForTab(
-      prevProps.threadInfo,
-      'delete',
-    );
-
-    if (!permissionForDeleteTab && prevPermissionForDeleteTab) {
-      this.setTab('general');
-    }
-  }
-
   possiblyChangedValue(key: string) {
     const valueChanged =
       this.props.queuedChanges[key] !== null &&
@@ -482,6 +458,19 @@
       [changeThreadSettingsAction, dispatchActionPromise],
     );
 
+    React.useEffect(() => {
+      // TODO: nameInput.focus()
+      // (once ref is moved up to functional component)
+
+      if (
+        threadInfo &&
+        currentTabType !== 'general' &&
+        !hasPermissionForTab(threadInfo, currentTabType)
+      ) {
+        setCurrentTabType('general');
+      }
+    }, [currentTabType, hasPermissionForTab, threadInfo]);
+
     if (!threadInfo) {
       return (
         <Modal onClose={modalContext.clearModal} name="Invalid thread">