diff --git a/CHANGES.rst b/CHANGES.rst
index fb17ada..62bb4a3 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -9,6 +9,18 @@ Version 0.5
   * Add ``coverage.json`` function.
   * Add ``coverage.lcov`` function.
 
+* Improve ``language/vimscript`` module.
+
+  * Add ``primula.annotate`` function.
+  * Add ``primula.combine`` function.
+  * Add ``primula.erase`` function.
+  * Add ``primula.html`` function.
+  * Add ``primula.json`` function.
+  * Add ``primula.lcov`` function.
+  * Add ``primula.report`` function.
+  * Add ``primula.run`` function.
+  * Add ``primula.xml`` function.
+
 
 Version 0.4
 -----------
diff --git a/doc/language/vimscript.rst b/doc/language/vimscript.rst
index 59107c8..0019795 100644
--- a/doc/language/vimscript.rst
+++ b/doc/language/vimscript.rst
@@ -38,6 +38,70 @@ covimerage.xml(...args)
 ``covimerage.xml`` represents ``covimerage xml``.
 
 
+vimscript.primula(...args)
+--------------------------
+
+``vimscript.primula`` represents ``primula``, and its commands are defined as
+properties of this function.
+
+Requirements
+  - `Primula <https://github.com/hattya/primula>`_
+
+
+primula.annotate(...args)
+~~~~~~~~~~~~~~~~~~~~~~~~~
+
+``primula.annotate`` represents ``primula annotate``.
+
+
+primula.combine(...args)
+~~~~~~~~~~~~~~~~~~~~~~~~
+
+``primula.combine`` represents ``primula combine``.
+
+
+primula.erase(...args)
+~~~~~~~~~~~~~~~~~~~~~~
+
+``primula.erase`` represents ``primula erase``.
+
+
+primula.html(...args)
+~~~~~~~~~~~~~~~~~~~~~
+
+``primula.html`` represents ``primula html``.
+
+
+primula.json(...args)
+~~~~~~~~~~~~~~~~~~~~~
+
+``primula.json`` represents ``primula json``.
+
+
+primula.lcov(...args)
+~~~~~~~~~~~~~~~~~~~~~
+
+``primula.lcov`` represents ``primula lcov``.
+
+
+primula.report(...args)
+~~~~~~~~~~~~~~~~~~~~~~~
+
+``primula.report`` represents ``primula report``.
+
+
+primula.run(...args)
+~~~~~~~~~~~~~~~~~~~~
+
+``primula.run`` represents ``primula run``.
+
+
+primula.xml(...args)
+~~~~~~~~~~~~~~~~~~~~
+
+``primula.xml`` represents ``primula xml``.
+
+
 vimscript.themis(...args)
 -------------------------
 
diff --git a/lib/language/vimscript.js b/lib/language/vimscript.js
index e7f0591..231cde3 100644
--- a/lib/language/vimscript.js
+++ b/lib/language/vimscript.js
@@ -1,7 +1,7 @@
 //
 // aster :: language/vimscript.js
 //
-//   Copyright (c) 2017-2020 Akinori Hattori <hattya@gmail.com>
+//   Copyright (c) 2017-2024 Akinori Hattori <hattya@gmail.com>
 //
 //   SPDX-License-Identifier: MIT
 //
@@ -42,6 +42,56 @@ covimerage.xml = function() {
   return covimerage.apply(null, ['xml'].concat(Array.prototype.slice.call(arguments)));
 };
 
+var primula = exports.primula = function primula() {
+  if (!os.whence('primula')) {
+    aster.notify('failure', language.prefix + 'primula', 'primula not found!');
+    return true;
+  }
+
+  return language.system({
+    args: ['primula'].concat(Array.prototype.slice.call(arguments)),
+    title: 'primula',
+    success: arguments[0] + ' passed',
+    failure: arguments[0] + ' failed',
+  });
+};
+
+primula.annotate = function annotate() {
+  return primula.apply(null, ['annotate'].concat(Array.prototype.slice.call(arguments)));
+};
+
+primula.combine = function combine() {
+  return primula.apply(null, ['combine'].concat(Array.prototype.slice.call(arguments)));
+};
+
+primula.erase = function erase() {
+  return primula.apply(null, ['erase'].concat(Array.prototype.slice.call(arguments)));
+};
+
+primula.html = function html() {
+  return primula.apply(null, ['html'].concat(Array.prototype.slice.call(arguments)));
+};
+
+primula.json = function json() {
+  return primula.apply(null, ['json'].concat(Array.prototype.slice.call(arguments)));
+};
+
+primula.lcov = function lcov() {
+  return primula.apply(null, ['lcov'].concat(Array.prototype.slice.call(arguments)));
+};
+
+primula.report = function report() {
+  return primula.apply(null, ['report'].concat(Array.prototype.slice.call(arguments)));
+};
+
+primula.run = function run() {
+  return primula.apply(null, ['run'].concat(Array.prototype.slice.call(arguments)));
+};
+
+primula.xml = function xml() {
+  return primula.apply(null, ['xml'].concat(Array.prototype.slice.call(arguments)));
+};
+
 exports.themis = function themis() {
   var script = 'themis';
   if (!os.whence(script)) {
diff --git a/std.go b/std.go
index f7867f5..870690a 100644
--- a/std.go
+++ b/std.go
@@ -483,7 +483,7 @@ exports.rst2html = function rst2html(object) {
 	"language/vimscript.js": []byte(`//
 // aster :: language/vimscript.js
 //
-//   Copyright (c) 2017-2020 Akinori Hattori <hattya@gmail.com>
+//   Copyright (c) 2017-2024 Akinori Hattori <hattya@gmail.com>
 //
 //   SPDX-License-Identifier: MIT
 //
@@ -524,6 +524,56 @@ covimerage.xml = function() {
   return covimerage.apply(null, ['xml'].concat(Array.prototype.slice.call(arguments)));
 };
 
+var primula = exports.primula = function primula() {
+  if (!os.whence('primula')) {
+    aster.notify('failure', language.prefix + 'primula', 'primula not found!');
+    return true;
+  }
+
+  return language.system({
+    args: ['primula'].concat(Array.prototype.slice.call(arguments)),
+    title: 'primula',
+    success: arguments[0] + ' passed',
+    failure: arguments[0] + ' failed',
+  });
+};
+
+primula.annotate = function annotate() {
+  return primula.apply(null, ['annotate'].concat(Array.prototype.slice.call(arguments)));
+};
+
+primula.combine = function combine() {
+  return primula.apply(null, ['combine'].concat(Array.prototype.slice.call(arguments)));
+};
+
+primula.erase = function erase() {
+  return primula.apply(null, ['erase'].concat(Array.prototype.slice.call(arguments)));
+};
+
+primula.html = function html() {
+  return primula.apply(null, ['html'].concat(Array.prototype.slice.call(arguments)));
+};
+
+primula.json = function json() {
+  return primula.apply(null, ['json'].concat(Array.prototype.slice.call(arguments)));
+};
+
+primula.lcov = function lcov() {
+  return primula.apply(null, ['lcov'].concat(Array.prototype.slice.call(arguments)));
+};
+
+primula.report = function report() {
+  return primula.apply(null, ['report'].concat(Array.prototype.slice.call(arguments)));
+};
+
+primula.run = function run() {
+  return primula.apply(null, ['run'].concat(Array.prototype.slice.call(arguments)));
+};
+
+primula.xml = function xml() {
+  return primula.apply(null, ['xml'].concat(Array.prototype.slice.call(arguments)));
+};
+
 exports.themis = function themis() {
   var script = 'themis';
   if (!os.whence(script)) {
diff --git a/test/language/vimscript.spec.js b/test/language/vimscript.spec.js
index 6e55143..cca9d3e 100644
--- a/test/language/vimscript.spec.js
+++ b/test/language/vimscript.spec.js
@@ -1,7 +1,7 @@
 //
 // aster :: language/vimscript.spec.js
 //
-//   Copyright (c) 2020-2021 Akinori Hattori <hattya@gmail.com>
+//   Copyright (c) 2020-2024 Akinori Hattori <hattya@gmail.com>
 //
 //   SPDX-License-Identifier: MIT
 //
@@ -100,6 +100,75 @@ describe('language', () => {
       });
     });
 
+    describe('.primula()', () => {
+      it('should notify "primula not found"', () => {
+        os.whence.mockReturnValueOnce(false);
+
+        expect(vimscript.primula('--version')).toBe(true);
+        expect(os.whence).lastCalledWith('primula');
+        expect(aster.notify).lastCalledWith('failure', 'aster: primula', 'primula not found!');
+      });
+
+      it('should execute `primula --version`', () => {
+        os.whence.mockReturnValueOnce(true);
+        language.system.mockReturnValueOnce(false);
+
+        expect(vimscript.primula('--version')).toBe(false);
+        expect(language.system).lastCalledWith({
+          args: ['primula', '--version'],
+          options: undefined,
+          title: 'primula',
+          success: '--version passed',
+          failure: '--version failed',
+        });
+      });
+    });
+
+    describe('.primula', () => {
+      describe.each([
+        ['annotate'],
+        ['combine'],
+        ['erase'],
+        ['html'],
+        ['json'],
+        ['lcov'],
+        ['report'],
+        ['xml'],
+      ])('.%s()', (cmd) => {
+        it(`should execute \`primula ${cmd}\``, () => {
+          os.whence.mockReturnValueOnce(true);
+          language.system.mockReturnValueOnce(false);
+
+          expect(vimscript.primula[cmd]()).toBe(false);
+          expect(os.whence).lastCalledWith('primula');
+          expect(language.system).lastCalledWith({
+            args: ['primula', cmd],
+            options: undefined,
+            title: 'primula',
+            success: `${cmd} passed`,
+            failure: `${cmd} failed`,
+          });
+        });
+      });
+
+      describe('.run()', () => {
+        it('should execute `primula run themis --reporter dot`', () => {
+          os.whence.mockReturnValueOnce(true);
+          language.system.mockReturnValueOnce(false);
+
+          expect(vimscript.primula.run('themis', '--reporter', 'dot')).toBe(false);
+          expect(os.whence).lastCalledWith('primula');
+          expect(language.system).lastCalledWith({
+            args: ['primula', 'run', 'themis', '--reporter', 'dot'],
+            options: undefined,
+            title: 'primula',
+            success: 'run passed',
+            failure: 'run failed',
+          });
+        });
+      });
+    });
+
     describe('.themis()', () => {
       it('should notify "themis not found"', () => {
         os.whence.mockClear().mockReturnValue(false);