diff --git a/src/cm_adapter.ts b/src/cm_adapter.ts
index 391f784..62cf1be 100644
--- a/src/cm_adapter.ts
+++ b/src/cm_adapter.ts
@@ -5,6 +5,7 @@ import { RegExpCursor, setSearchQuery, SearchQuery } from "@codemirror/search"
 import {
   insertNewlineAndIndent, indentMore, indentLess, indentSelection, cursorCharLeft,
   undo, redo, cursorLineBoundaryBackward, cursorLineBoundaryForward, cursorCharBackward, 
+  toggleLineComment
 } from "@codemirror/commands"
 import {vimState, CM5RangeInterface} from "./types"
 
@@ -135,6 +136,7 @@ export class CodeMirror {
   static Pos = Pos;
   static StringStream = StringStream as unknown as StringStream & { new(_: string): StringStream }
   static commands = {
+    toggleLineComment: function (cm: CodeMirror) { toggleLineComment(cm.cm6) },
     cursorCharLeft: function (cm: CodeMirror) { cursorCharLeft(cm.cm6); },
     redo: function (cm: CodeMirror) { runHistoryCommand(cm, false); },
     undo: function (cm: CodeMirror) { runHistoryCommand(cm, true); },
@@ -427,7 +429,7 @@ export class CodeMirror {
   };
 
   execCommand(name: string) {
-    if (name == "indentAuto") CodeMirror.commands.indentAuto(this);
+    if (CodeMirror.commands.hasOwnProperty(name)) CodeMirror.commands[name](this);
     else if (name == "goLineLeft") cursorLineBoundaryBackward(this.cm6);
     else if (name == "goLineRight") {
       cursorLineBoundaryForward(this.cm6);
diff --git a/src/vim.js b/src/vim.js
index 237858b..dee70d1 100644
--- a/src/vim.js
+++ b/src/vim.js
@@ -175,6 +175,7 @@ export function initVim(CM) {
     { keys: 'g~', type: 'operator', operator: 'changeCase' },
     { keys: 'gu', type: 'operator', operator: 'changeCase', operatorArgs: {toLower: true}, isEdit: true },
     { keys: 'gU', type: 'operator', operator: 'changeCase', operatorArgs: {toLower: false}, isEdit: true },
+    { keys: 'gc', type: 'operator', operator: 'toggleComment', isEdit: true },
     { keys: 'n', type: 'motion', motion: 'findNext', motionArgs: { forward: true, toJumplist: true }},
     { keys: 'N', type: 'motion', motion: 'findNext', motionArgs: { forward: false, toJumplist: true }},
     { keys: 'gn', type: 'motion', motion: 'findAndSelectNextInclusive', motionArgs: { forward: true }},
@@ -2861,6 +2862,10 @@ export function initVim(CM) {
       if (endRow > from && operatorArgs.linewise) endRow--;
       return operatorArgs.keepCursor ? oldAnchor : new Pos(endRow, 0);
     },
+    toggleComment: function(cm, _args, ranges, oldAnchor, newHead) {
+      cm.execCommand("toggleLineComment");
+      return newHead;
+    },
     changeCase: function(cm, args, ranges, oldAnchor, newHead) {
       var selections = cm.getSelections();
       var swapped = [];
diff --git a/test/vim_test.js b/test/vim_test.js
index 52a42ca..79c6464 100644
--- a/test/vim_test.js
+++ b/test/vim_test.js
@@ -1290,6 +1290,12 @@ testVim('s_visual_block', function(cm, vim, helpers) {
   eq('1hello{\n  world\n', cm.getValue());
 }, {value: '1234\n5678\nabcdefg\n'});
 
+testVim('gcc', function(cm, vim, helpers) {
+  helpers.doKeys('g', 'c', 'c');
+  eq('// var line1\nline2\nline3', cm.getValue());
+  helpers.doKeys('2', 'g', 'c', 'c');
+  eq('// // var line1\n// line2\nline3', cm.getValue());
+}, { value: 'var line1\nline2\nline3', mode: ''});
 // Test mode change event. It should only fire once per mode transition.
 testVim('on_mode_change', async function(cm, vim, helpers) {
   var modeHist = [];