diff --git a/src/chrome/content.ts b/src/chrome/content.ts
index e0b463c..ffcd5e9 100644
--- a/src/chrome/content.ts
+++ b/src/chrome/content.ts
@@ -8,6 +8,7 @@ import {
     getGithubCommitUrlParams,
     createReactRoot,
     getGithubBlobUrlParams,
+    getGithubCommitWithinPullUrlParams,
 } from './web'
 import gitHubInjection from 'github-injection'
 
@@ -128,6 +129,15 @@ async function run() {
         return
     }
 
+    const commitWithinPullParams = getGithubCommitWithinPullUrlParams(url)
+    if (commitWithinPullParams) {
+        const { owner, repo, pull, sha } = commitWithinPullParams
+        console.log('Found commit diff within pull: ', owner, repo, pull, sha)
+        // TODO: understand if more things are needed here for this special case
+        await injectCommitDiff(owner, repo, sha, window.document)
+        return
+    }
+
     const blobParams = getGithubBlobUrlParams(url)
     if (blobParams) {
         const { owner, repo, sha, filename } = blobParams
diff --git a/src/chrome/web.test.ts b/src/chrome/web.test.ts
index e17f77d..82534d0 100644
--- a/src/chrome/web.test.ts
+++ b/src/chrome/web.test.ts
@@ -8,6 +8,7 @@ import {
     getSupportedWebDiffElements,
     createReactRoot,
     getGithubBlobUrlParams,
+    getGithubCommitWithinPullUrlParams,
 } from './web'
 
 const githubPullHtmlSnippet = `
@@ -147,6 +148,29 @@ describe('Function getGithubCommitUrlParams', () => {
     })
 })
 
+describe('Function getGithubCommitWithinPullUrlParams', () => {
+    it('gets params out of a valid github commit link within a PR', () => {
+        const url =
+            'https://github.com/KittyCAD/diff-samples/pull/2/commits/1dc0d43a94dba95279fcfc112bb5dd4dfaac01ae'
+        const params = getGithubCommitWithinPullUrlParams(url)
+        expect(params).toBeDefined()
+        const { owner, repo, pull, sha } = params!
+        expect(owner).toEqual('KittyCAD')
+        expect(repo).toEqual('diff-samples')
+        expect(pull).toEqual(2)
+        expect(sha).toEqual('1dc0d43a94dba95279fcfc112bb5dd4dfaac01ae')
+    })
+
+    it("doesn't match other URLs", () => {
+        expect(getGithubCommitWithinPullUrlParams('http://google.com')).toBeUndefined()
+        expect(
+            getGithubCommitWithinPullUrlParams(
+                'https://github.com/KittyCAD/litterbox/commit/4ddf899550addf41d6bf1b790ce79e46501411b3'
+            )
+        ).toBeUndefined()
+    })
+})
+
 describe('Function getGithubBlobUrlParams', () => {
     it('gets params out of a valid github blob link', () => {
         const url =
diff --git a/src/chrome/web.ts b/src/chrome/web.ts
index c41cec6..ab00aa2 100644
--- a/src/chrome/web.ts
+++ b/src/chrome/web.ts
@@ -44,6 +44,34 @@ export function getGithubCommitUrlParams(
     return { owner, repo, sha }
 }
 
+export type GithubCommitWithinPullUrlParams = {
+    owner: string
+    repo: string
+    pull: number
+    sha: string
+}
+
+export function getGithubCommitWithinPullUrlParams(
+    url: string
+): GithubCommitWithinPullUrlParams | undefined {
+    const pullRe =
+        /https:\/\/github\.com\/([a-zA-Z0-9_.-]+)\/([a-zA-Z0-9_.-]+)\/pull\/(\d+)\/commits\/(\w+)/
+    const result = pullRe.exec(url)
+    if (!result) {
+        return undefined
+    }
+
+    const [, owner, repo, pull, sha] = result
+    console.log(
+        'Found a supported Github Commit witin Pull URL:',
+        owner,
+        repo,
+        pull,
+        sha
+    )
+    return { owner, repo, sha, pull: parseInt(pull) }
+}
+
 export type GithubBlobUrlParams = {
     owner: string
     repo: string
diff --git a/tests/extension.spec.ts b/tests/extension.spec.ts
index 6c654b4..6000fb8 100644
--- a/tests/extension.spec.ts
+++ b/tests/extension.spec.ts
@@ -68,6 +68,20 @@ test('pull request diff with a modified .obj file', async ({
     expect(screenshot2).toMatchSnapshot()
 })
 
+test('commit diff within pull request with a modified .stl file', async ({
+    page,
+    authorizedBackground,
+}) => {
+    const url = 'https://github.com/KittyCAD/diff-samples/pull/2/commits/1dc0d43a94dba95279fcfc112bb5dd4dfaac01ae'
+    const element = await getFirstDiffElement(page, url, 'stl')
+    const screenshot = await element.screenshot()
+    expect(screenshot).toMatchSnapshot()
+
+    await enableCombined(page, element)
+    const screenshot2 = await element.screenshot()
+    expect(screenshot2).toMatchSnapshot()
+})
+
 test('pull request diff with a modified .step file', async ({
     page,
     authorizedBackground,
diff --git a/tests/extension.spec.ts-snapshots/commit-diff-within-pull-request-with-a-modified-stl-file-1-chromium-linux.png b/tests/extension.spec.ts-snapshots/commit-diff-within-pull-request-with-a-modified-stl-file-1-chromium-linux.png
new file mode 100644
index 0000000..b6644f4
Binary files /dev/null and b/tests/extension.spec.ts-snapshots/commit-diff-within-pull-request-with-a-modified-stl-file-1-chromium-linux.png differ
diff --git a/tests/extension.spec.ts-snapshots/commit-diff-within-pull-request-with-a-modified-stl-file-2-chromium-linux.png b/tests/extension.spec.ts-snapshots/commit-diff-within-pull-request-with-a-modified-stl-file-2-chromium-linux.png
new file mode 100644
index 0000000..99dcc3d
Binary files /dev/null and b/tests/extension.spec.ts-snapshots/commit-diff-within-pull-request-with-a-modified-stl-file-2-chromium-linux.png differ