diff --git a/lib/command.js b/lib/command.js
index cd6614f0c..1a1424c5e 100644
--- a/lib/command.js
+++ b/lib/command.js
@@ -946,6 +946,7 @@ Expecting one of '${allowedValues.join("', '")}'`);
 
     // Not checking for help first. Unlikely to have mandatory and executable, and can't robustly test for help flags in external command.
     this._checkForMissingMandatoryOptions();
+    this._checkForConflictingOptions();
 
     // executableFile and executableDir might be full path, or just a name
     let executableFile = subcommand._executableFile || `${this._name}-${subcommand._name}`;
@@ -1294,7 +1295,7 @@ Expecting one of '${allowedValues.join("', '")}'`);
 
   /**
    * Display an error message if a mandatory option does not have a value.
-   * Lazy calling after checking for help flags from leaf subcommand.
+   * Called after checking for help flags in leaf subcommand.
    *
    * @api private
    */
@@ -1311,11 +1312,11 @@ Expecting one of '${allowedValues.join("', '")}'`);
   }
 
   /**
-   * Display an error message if conflicting options are used together.
+   * Display an error message if conflicting options are used together in this.
    *
    * @api private
    */
-  _checkForConflictingOptions() {
+  _checkForConflictingLocalOptions() {
     const definedNonDefaultOptions = this.options.filter(
       (option) => {
         const optionKey = option.attributeName();
@@ -1340,6 +1341,19 @@ Expecting one of '${allowedValues.join("', '")}'`);
     });
   }
 
+  /**
+   * Display an error message if conflicting options are used together.
+   * Called after checking for help flags in leaf subcommand.
+   *
+   * @api private
+   */
+  _checkForConflictingOptions() {
+    // Walk up hierarchy so can call in subcommand after checking for displaying help.
+    for (let cmd = this; cmd; cmd = cmd.parent) {
+      cmd._checkForConflictingLocalOptions();
+    }
+  }
+
   /**
    * Parse options from `argv` removing known options,
    * and return argv split into operands and unknown arguments.
diff --git a/tests/command.conflicts.test.js b/tests/options.conflicts.test.js
similarity index 83%
rename from tests/command.conflicts.test.js
rename to tests/options.conflicts.test.js
index 8e2ce9860..72884b802 100644
--- a/tests/command.conflicts.test.js
+++ b/tests/options.conflicts.test.js
@@ -1,3 +1,4 @@
+const path = require('path');
 const commander = require('../');
 
 describe('command with conflicting options', () => {
@@ -7,7 +8,8 @@ describe('command with conflicting options', () => {
     program
       .exitOverride()
       .configureOutput({
-        writeErr: () => {}
+        writeErr: () => {},
+        writeOut: () => {}
       })
       .command('foo')
       .addOption(new commander.Option('-s, --silent', "Don't print anything").env('SILENT'))
@@ -253,4 +255,57 @@ describe('command with conflicting options', () => {
       program.parse('node test.js bar --a --b'.split(' '));
     }).toThrow("error: option '--b' cannot be used with option '--a'");
   });
+
+  test('when conflict on program calling action subcommand then throw conflict', () => {
+    const { program } = makeProgram();
+    let exception;
+
+    program
+      .addOption(new commander.Option('--black'))
+      .addOption(new commander.Option('--white').conflicts('black'));
+
+    try {
+      program.parse('--white --black foo'.split(' '), { from: 'user' });
+    } catch (err) {
+      exception = err;
+    }
+    expect(exception).not.toBeUndefined();
+    expect(exception.code).toBe('commander.conflictingOption');
+  });
+
+  test('when conflict on program calling action subcommand with help then show help', () => {
+    const { program } = makeProgram();
+    let exception;
+
+    program
+      .addOption(new commander.Option('--black'))
+      .addOption(new commander.Option('--white').conflicts('black'));
+
+    try {
+      program.parse('--white --black foo --help'.split(' '), { from: 'user' });
+    } catch (err) {
+      exception = err;
+    }
+    expect(exception).not.toBeUndefined();
+    expect(exception.code).toBe('commander.helpDisplayed');
+  });
+
+  test('when conflict on program calling external subcommand then throw conflict', () => {
+    const { program } = makeProgram();
+    let exception;
+
+    program
+      .addOption(new commander.Option('--black'))
+      .addOption(new commander.Option('--white').conflicts('black'));
+    const pm = path.join(__dirname, './fixtures/pm');
+    program.command('ext', 'external command', { executableFile: pm });
+
+    try {
+      program.parse('--white --black ext'.split(' '), { from: 'user' });
+    } catch (err) {
+      exception = err;
+    }
+    expect(exception).not.toBeUndefined();
+    expect(exception.code).toBe('commander.conflictingOption');
+  });
 });