diff --git a/CHANGELOG.md b/CHANGELOG.md
index c4b72dd357..147b944405 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,7 +4,11 @@ Please add one entry in this file for each change in Yarn's behavior. Use the sa
 
 ## Master
 
-- Fixes handling of empty string entries for bin in package.json
+- Fixes the `extensions` option when used by `resolveRequest`
+
+  [#6479](https://github.com/yarnpkg/yarn/pull/6479) - [**Maël Nison**](https://twitter.com/arcanis)
+
+- Fixes handling of empty string entries for `bin` in package.json
 
   [#6515](https://github.com/yarnpkg/yarn/pull/6515) - [**Ryan Burrows**](https://github.com/rhburrows)
 
diff --git a/packages/pkg-tests/pkg-tests-specs/sources/index.js b/packages/pkg-tests/pkg-tests-specs/sources/index.js
index c2ac091cba..f000a152ae 100644
--- a/packages/pkg-tests/pkg-tests-specs/sources/index.js
+++ b/packages/pkg-tests/pkg-tests-specs/sources/index.js
@@ -4,5 +4,6 @@ exports.basic = require('./basic');
 exports.dragon = require('./dragon');
 exports.lock = require('./lock');
 exports.pnp = require('./pnp');
+exports.pnpapiV1 = require('./pnpapi-v1');
 exports.script = require('./script');
 exports.workspace = require('./workspace');
diff --git a/packages/pkg-tests/pkg-tests-specs/sources/pnpapi-v1.js b/packages/pkg-tests/pkg-tests-specs/sources/pnpapi-v1.js
new file mode 100644
index 0000000000..e56fb700e8
--- /dev/null
+++ b/packages/pkg-tests/pkg-tests-specs/sources/pnpapi-v1.js
@@ -0,0 +1,88 @@
+const {fs: {writeFile, writeJson}} = require('pkg-tests-core');
+
+module.exports = makeTemporaryEnv => {
+  describe(`Plug'n'Play API (v1)`, () => {
+    test(
+      `it should expost VERSIONS`,
+      makeTemporaryEnv({}, {plugNPlay: true}, async ({path, run, source}) => {
+        await run(`install`);
+
+        await expect(source(`require('pnpapi').VERSIONS`)).resolves.toMatchObject({std: 1});
+      }),
+    );
+
+    test(
+      `it should expost resolveToUnqualified`,
+      makeTemporaryEnv({}, {plugNPlay: true}, async ({path, run, source}) => {
+        await run(`install`);
+
+        await expect(source(`typeof require('pnpapi').resolveToUnqualified`)).resolves.toEqual(`function`);
+      }),
+    );
+
+    test(
+      `it should expost resolveToUnqualified`,
+      makeTemporaryEnv({}, {plugNPlay: true}, async ({path, run, source}) => {
+        await run(`install`);
+
+        await expect(source(`typeof require('pnpapi').resolveUnqualified`)).resolves.toEqual(`function`);
+      }),
+    );
+
+    test(
+      `it should expost resolveToUnqualified`,
+      makeTemporaryEnv({}, {plugNPlay: true}, async ({path, run, source}) => {
+        await run(`install`);
+
+        await expect(source(`typeof require('pnpapi').resolveRequest`)).resolves.toEqual(`function`);
+      }),
+    );
+
+    describe(`resolveRequest`, () => {
+      test(
+        `it should return null for builtins`,
+        makeTemporaryEnv({}, {plugNPlay: true}, async ({path, run, source}) => {
+          await run(`install`);
+
+          await expect(source(`require('pnpapi').resolveRequest('fs', '${path}/')`)).resolves.toEqual(null);
+        }),
+      );
+
+      test(
+        `it should support the 'considerBuiltins' option`,
+        makeTemporaryEnv(
+          {
+            dependencies: {[`fs`]: `link:./fs`},
+          },
+          {plugNPlay: true},
+          async ({path, run, source}) => {
+            await writeFile(`${path}/fs/index.js`, `module.exports = 'Hello world';`);
+            await writeJson(`${path}/fs/package.json`, {
+              name: `fs`,
+              version: `1.0.0`,
+            });
+
+            await run(`install`);
+
+            await expect(
+              source(`require('pnpapi').resolveRequest('fs', '${path}/', {considerBuiltins: false})`),
+            ).resolves.toEqual(`${path}/fs/index.js`);
+          },
+        ),
+      );
+
+      test(
+        `it should support the 'extensions' option`,
+        makeTemporaryEnv({}, {plugNPlay: true}, async ({path, run, source}) => {
+          await writeFile(`${path}/foo.bar`, `hello world`);
+
+          await run(`install`);
+
+          await expect(
+            source(`require('pnpapi').resolveRequest('./foo', '${path}/', {extensions: ['.bar']})`),
+          ).resolves.toEqual(`${path}/foo.bar`);
+        }),
+      );
+    });
+  });
+};
diff --git a/packages/pkg-tests/yarn.test.js b/packages/pkg-tests/yarn.test.js
index d3727b592f..25b5d968f0 100644
--- a/packages/pkg-tests/yarn.test.js
+++ b/packages/pkg-tests/yarn.test.js
@@ -12,6 +12,7 @@ const {
   dragon: dragonSpecs,
   lock: lockSpecs,
   pnp: pnpSpecs,
+  pnpapiV1: pnpapiV1Specs,
   script: scriptSpecs,
   workspace: workspaceSpecs,
 } = require(`pkg-tests-specs`);
@@ -74,4 +75,5 @@ lockSpecs(pkgDriver);
 scriptSpecs(pkgDriver);
 workspaceSpecs(pkgDriver);
 pnpSpecs(pkgDriver);
+pnpapiV1Specs(pkgDriver);
 dragonSpecs(pkgDriver);
diff --git a/src/util/generate-pnp-map-api.tpl.js b/src/util/generate-pnp-map-api.tpl.js
index d8f5152100..f594353b07 100644
--- a/src/util/generate-pnp-map-api.tpl.js
+++ b/src/util/generate-pnp-map-api.tpl.js
@@ -518,7 +518,7 @@ exports.resolveRequest = function resolveRequest(request, issuer, {considerBuilt
         }
 
         try {
-          exports.resolveToUnqualified(request, realIssuer, {extensions});
+          exports.resolveToUnqualified(request, realIssuer, {considerBuiltins});
         } catch (error) {
           // If an error was thrown, the problem doesn't seem to come from a path not being normalized, so we
           // can just throw the original error which was legit.
@@ -547,7 +547,7 @@ exports.resolveRequest = function resolveRequest(request, issuer, {considerBuilt
   }
 
   try {
-    return exports.resolveUnqualified(unqualifiedPath);
+    return exports.resolveUnqualified(unqualifiedPath, {extensions});
   } catch (resolutionError) {
     if (resolutionError.code === 'QUALIFIED_PATH_RESOLUTION_FAILED') {
       Object.assign(resolutionError.data, {request, issuer});