diff --git a/lib/platform/azure/index.spec.ts b/lib/platform/azure/index.spec.ts
index 592b6d769245e97d3a9d7475d6c0bea7dcc975d5..a2a2cf2f42aeaba879b82b2d4623cccdb9ca6734 100644
--- a/lib/platform/azure/index.spec.ts
+++ b/lib/platform/azure/index.spec.ts
@@ -1250,6 +1250,24 @@ describe('platform/azure/index', () => {
       const res = await azure.getJsonFile('file.json');
       expect(res).toEqual(data);
     });
+    it('returns file content in json5 format', async () => {
+      const json5Data = `
+        { 
+          // json5 comment
+          foo: 'bar' 
+        }
+      `;
+      azureApi.gitApi.mockImplementationOnce(
+        () =>
+          ({
+            getItemContent: jest.fn(() =>
+              Promise.resolve(Readable.from(json5Data))
+            ),
+          } as any)
+      );
+      const res = await azure.getJsonFile('file.json5');
+      expect(res).toEqual({ foo: 'bar' });
+    });
     it('throws on malformed JSON', async () => {
       azureApi.gitApi.mockImplementationOnce(
         () =>
diff --git a/lib/platform/azure/index.ts b/lib/platform/azure/index.ts
index f0bfd15f2004e1971f058370fd464514457710d0..079286f474d3685b5d3612c806e205bfcb0b7bb1 100644
--- a/lib/platform/azure/index.ts
+++ b/lib/platform/azure/index.ts
@@ -8,6 +8,7 @@ import {
   PullRequestStatus,
 } from 'azure-devops-node-api/interfaces/GitInterfaces';
 import delay from 'delay';
+import JSON5 from 'json5';
 import { PlatformId } from '../../constants';
 import { REPOSITORY_EMPTY } from '../../constants/error-messages';
 import { logger } from '../../logger';
@@ -135,6 +136,9 @@ export async function getJsonFile(
   repoName?: string
 ): Promise<any | null> {
   const raw = await getRawFile(fileName, repoName);
+  if (fileName.endsWith('.json5')) {
+    return JSON5.parse(raw);
+  }
   return JSON.parse(raw);
 }
 
diff --git a/lib/platform/bitbucket-server/__snapshots__/index.spec.ts.snap b/lib/platform/bitbucket-server/__snapshots__/index.spec.ts.snap
index 6f51fedf04120adfc1950ceac26b7b65a7dbf2e5..ac53786634db0848b3c8f3cbc2f79a8aef0ab708 100644
--- a/lib/platform/bitbucket-server/__snapshots__/index.spec.ts.snap
+++ b/lib/platform/bitbucket-server/__snapshots__/index.spec.ts.snap
@@ -2068,6 +2068,47 @@ Array [
 ]
 `;
 
+exports[`platform/bitbucket-server/index endpoint with no path getJsonFile() returns file content in json5 format 1`] = `
+Array [
+  Object {
+    "headers": Object {
+      "accept": "application/json",
+      "accept-encoding": "gzip, deflate, br",
+      "authorization": "Basic YWJjOjEyMw==",
+      "host": "stash.renovatebot.com",
+      "user-agent": "RenovateBot/0.0.0-semantic-release (https://github.com/renovatebot/renovate)",
+      "x-atlassian-token": "no-check",
+    },
+    "method": "GET",
+    "url": "https://stash.renovatebot.com/rest/api/1.0/projects/SOME/repos/repo",
+  },
+  Object {
+    "headers": Object {
+      "accept": "application/json",
+      "accept-encoding": "gzip, deflate, br",
+      "authorization": "Basic YWJjOjEyMw==",
+      "host": "stash.renovatebot.com",
+      "user-agent": "RenovateBot/0.0.0-semantic-release (https://github.com/renovatebot/renovate)",
+      "x-atlassian-token": "no-check",
+    },
+    "method": "GET",
+    "url": "https://stash.renovatebot.com/rest/api/1.0/projects/SOME/repos/repo/branches/default",
+  },
+  Object {
+    "headers": Object {
+      "accept": "application/json",
+      "accept-encoding": "gzip, deflate, br",
+      "authorization": "Basic YWJjOjEyMw==",
+      "host": "stash.renovatebot.com",
+      "user-agent": "RenovateBot/0.0.0-semantic-release (https://github.com/renovatebot/renovate)",
+      "x-atlassian-token": "no-check",
+    },
+    "method": "GET",
+    "url": "https://stash.renovatebot.com/rest/api/1.0/projects/SOME/repos/repo/browse/file.json5?limit=20000",
+  },
+]
+`;
+
 exports[`platform/bitbucket-server/index endpoint with no path getJsonFile() throws on errors 1`] = `
 Array [
   Object {
@@ -6443,6 +6484,47 @@ Array [
 ]
 `;
 
+exports[`platform/bitbucket-server/index endpoint with path getJsonFile() returns file content in json5 format 1`] = `
+Array [
+  Object {
+    "headers": Object {
+      "accept": "application/json",
+      "accept-encoding": "gzip, deflate, br",
+      "authorization": "Basic YWJjOjEyMw==",
+      "host": "stash.renovatebot.com",
+      "user-agent": "RenovateBot/0.0.0-semantic-release (https://github.com/renovatebot/renovate)",
+      "x-atlassian-token": "no-check",
+    },
+    "method": "GET",
+    "url": "https://stash.renovatebot.com/vcs/rest/api/1.0/projects/SOME/repos/repo",
+  },
+  Object {
+    "headers": Object {
+      "accept": "application/json",
+      "accept-encoding": "gzip, deflate, br",
+      "authorization": "Basic YWJjOjEyMw==",
+      "host": "stash.renovatebot.com",
+      "user-agent": "RenovateBot/0.0.0-semantic-release (https://github.com/renovatebot/renovate)",
+      "x-atlassian-token": "no-check",
+    },
+    "method": "GET",
+    "url": "https://stash.renovatebot.com/vcs/rest/api/1.0/projects/SOME/repos/repo/branches/default",
+  },
+  Object {
+    "headers": Object {
+      "accept": "application/json",
+      "accept-encoding": "gzip, deflate, br",
+      "authorization": "Basic YWJjOjEyMw==",
+      "host": "stash.renovatebot.com",
+      "user-agent": "RenovateBot/0.0.0-semantic-release (https://github.com/renovatebot/renovate)",
+      "x-atlassian-token": "no-check",
+    },
+    "method": "GET",
+    "url": "https://stash.renovatebot.com/vcs/rest/api/1.0/projects/SOME/repos/repo/browse/file.json5?limit=20000",
+  },
+]
+`;
+
 exports[`platform/bitbucket-server/index endpoint with path getJsonFile() throws on errors 1`] = `
 Array [
   Object {
diff --git a/lib/platform/bitbucket-server/index.spec.ts b/lib/platform/bitbucket-server/index.spec.ts
index 8b0d036d23998bac0c543b24d6303145cf1fc94c..2f77e0e4d03f0158d1d7082153d0ffa9c2360920 100644
--- a/lib/platform/bitbucket-server/index.spec.ts
+++ b/lib/platform/bitbucket-server/index.spec.ts
@@ -2109,6 +2109,26 @@ Followed by some information.
           expect(res).toEqual(data);
           expect(httpMock.getTrace()).toMatchSnapshot();
         });
+        it('returns file content in json5 format', async () => {
+          const json5Data = `
+          { 
+            // json5 comment
+            foo: 'bar' 
+          }
+        `;
+          const scope = await initRepo();
+          scope
+            .get(
+              `${urlPath}/rest/api/1.0/projects/SOME/repos/repo/browse/file.json5?limit=20000`
+            )
+            .reply(200, {
+              isLastPage: true,
+              lines: [{ text: json5Data }],
+            });
+          const res = await bitbucket.getJsonFile('file.json5');
+          expect(res).toEqual({ foo: 'bar' });
+          expect(httpMock.getTrace()).toMatchSnapshot();
+        });
         it('throws on malformed JSON', async () => {
           const scope = await initRepo();
           scope
diff --git a/lib/platform/bitbucket-server/index.ts b/lib/platform/bitbucket-server/index.ts
index 2a13acb49925af1487db6dc46304d2bee3be1194..04b8b1450fe06b7c6b5ef0dd57c488cd8959c210 100644
--- a/lib/platform/bitbucket-server/index.ts
+++ b/lib/platform/bitbucket-server/index.ts
@@ -1,6 +1,7 @@
 import url from 'url';
 import is from '@sindresorhus/is';
 import delay from 'delay';
+import JSON5 from 'json5';
 import type { PartialDeep } from 'type-fest';
 import { PlatformId } from '../../constants';
 import {
@@ -141,6 +142,9 @@ export async function getJsonFile(
   repo: string = config.repository
 ): Promise<any | null> {
   const raw = await getRawFile(fileName, repo);
+  if (fileName.endsWith('.json5')) {
+    return JSON5.parse(raw);
+  }
   return JSON.parse(raw);
 }
 
diff --git a/lib/platform/bitbucket/__snapshots__/index.spec.ts.snap b/lib/platform/bitbucket/__snapshots__/index.spec.ts.snap
index 8484e51d2693daf0f84e1a9f3803148d06167dd4..44df44b929326c7291030c749fca17c0dc7118d0 100644
--- a/lib/platform/bitbucket/__snapshots__/index.spec.ts.snap
+++ b/lib/platform/bitbucket/__snapshots__/index.spec.ts.snap
@@ -938,6 +938,32 @@ Array [
 ]
 `;
 
+exports[`platform/bitbucket/index getJsonFile() returns file content in json5 format 1`] = `
+Array [
+  Object {
+    "headers": Object {
+      "accept": "application/json",
+      "accept-encoding": "gzip, deflate, br",
+      "authorization": "Basic YWJjOjEyMw==",
+      "host": "api.bitbucket.org",
+      "user-agent": "RenovateBot/0.0.0-semantic-release (https://github.com/renovatebot/renovate)",
+    },
+    "method": "GET",
+    "url": "https://api.bitbucket.org/2.0/repositories/some/repo",
+  },
+  Object {
+    "headers": Object {
+      "accept-encoding": "gzip, deflate, br",
+      "authorization": "Basic YWJjOjEyMw==",
+      "host": "api.bitbucket.org",
+      "user-agent": "RenovateBot/0.0.0-semantic-release (https://github.com/renovatebot/renovate)",
+    },
+    "method": "GET",
+    "url": "https://api.bitbucket.org/2.0/repositories/some/repo/src/HEAD/file.json5",
+  },
+]
+`;
+
 exports[`platform/bitbucket/index getJsonFile() throws on errors 1`] = `
 Array [
   Object {
diff --git a/lib/platform/bitbucket/index.spec.ts b/lib/platform/bitbucket/index.spec.ts
index 2a59c36dedfc1dc84851990a3d70cabf81ba233c..3abe950b01aa589279db601f53d8f0e8233c7914 100644
--- a/lib/platform/bitbucket/index.spec.ts
+++ b/lib/platform/bitbucket/index.spec.ts
@@ -938,6 +938,21 @@ describe('platform/bitbucket/index', () => {
       expect(res).toEqual(data);
       expect(httpMock.getTrace()).toMatchSnapshot();
     });
+    it('returns file content in json5 format', async () => {
+      const json5Data = `
+        { 
+          // json5 comment
+          foo: 'bar' 
+        }
+      `;
+      const scope = await initRepoMock();
+      scope
+        .get('/2.0/repositories/some/repo/src/HEAD/file.json5')
+        .reply(200, json5Data);
+      const res = await bitbucket.getJsonFile('file.json5');
+      expect(res).toEqual({ foo: 'bar' });
+      expect(httpMock.getTrace()).toMatchSnapshot();
+    });
     it('throws on malformed JSON', async () => {
       const scope = await initRepoMock();
       scope
diff --git a/lib/platform/bitbucket/index.ts b/lib/platform/bitbucket/index.ts
index c2e4db583b4b14a3fbf2090246464ac48cf7006b..f203d77e29c7f0bcfa33d1ab440ba04838ced8e8 100644
--- a/lib/platform/bitbucket/index.ts
+++ b/lib/platform/bitbucket/index.ts
@@ -1,5 +1,6 @@
 import URL from 'url';
 import is from '@sindresorhus/is';
+import JSON5 from 'json5';
 import parseDiff from 'parse-diff';
 import { PlatformId } from '../../constants';
 import { REPOSITORY_NOT_FOUND } from '../../constants/error-messages';
@@ -123,6 +124,9 @@ export async function getJsonFile(
   repo: string = config.repository
 ): Promise<any | null> {
   const raw = await getRawFile(fileName, repo);
+  if (fileName.endsWith('.json5')) {
+    return JSON5.parse(raw);
+  }
   return JSON.parse(raw);
 }
 
diff --git a/lib/platform/gitea/index.spec.ts b/lib/platform/gitea/index.spec.ts
index 05b9a3de361c3de1650f039e06b6fb55aaaebaa6..5b41b8fb95c59fefc5d2cc841a52abd49fe2e6f5 100644
--- a/lib/platform/gitea/index.spec.ts
+++ b/lib/platform/gitea/index.spec.ts
@@ -1527,6 +1527,20 @@ describe('platform/gitea/index', () => {
       const res = await gitea.getJsonFile('file.json');
       expect(res).toEqual(data);
     });
+    it('returns file content in json5 format', async () => {
+      const json5Data = `
+        { 
+          // json5 comment
+          foo: 'bar' 
+        }
+      `;
+      helper.getRepoContents.mockResolvedValueOnce({
+        contentString: json5Data,
+      } as never);
+      await initFakeRepo({ full_name: 'some/repo' });
+      const res = await gitea.getJsonFile('file.json5');
+      expect(res).toEqual({ foo: 'bar' });
+    });
     it('throws on malformed JSON', async () => {
       helper.getRepoContents.mockResolvedValueOnce({
         contentString: '!@#',
diff --git a/lib/platform/gitea/index.ts b/lib/platform/gitea/index.ts
index fa055a6ce78e486600ca29a04c63b2e493bfb945..22b23eab39f69c03675fe0c85205151abfba9c8b 100644
--- a/lib/platform/gitea/index.ts
+++ b/lib/platform/gitea/index.ts
@@ -1,5 +1,6 @@
 import URL from 'url';
 import is from '@sindresorhus/is';
+import JSON5 from 'json5';
 import { lt } from 'semver';
 import { PlatformId } from '../../constants';
 import {
@@ -221,6 +222,9 @@ const platform: Platform = {
     repo: string = config.repository
   ): Promise<any | null> {
     const raw = await platform.getRawFile(fileName, repo);
+    if (fileName.endsWith('.json5')) {
+      return JSON5.parse(raw);
+    }
     return JSON.parse(raw);
   },
 
diff --git a/lib/platform/github/__snapshots__/index.spec.ts.snap b/lib/platform/github/__snapshots__/index.spec.ts.snap
index d8291824b1bc112856f778d66e13e6ba7b810222..42a296e4f2f717d0226125a1211ce9be7b6eb200 100644
--- a/lib/platform/github/__snapshots__/index.spec.ts.snap
+++ b/lib/platform/github/__snapshots__/index.spec.ts.snap
@@ -4964,6 +4964,66 @@ Array [
 ]
 `;
 
+exports[`platform/github/index getJsonFile() returns file content in json5 format 1`] = `
+Array [
+  Object {
+    "graphql": Object {
+      "query": Object {
+        "__vars": Object {
+          "$name": "String!",
+          "$owner": "String!",
+        },
+        "repository": Object {
+          "__args": Object {
+            "name": "$name",
+            "owner": "$owner",
+          },
+          "autoMergeAllowed": null,
+          "defaultBranchRef": Object {
+            "name": null,
+            "target": Object {
+              "oid": null,
+            },
+          },
+          "isArchived": null,
+          "isFork": null,
+          "mergeCommitAllowed": null,
+          "nameWithOwner": null,
+          "rebaseMergeAllowed": null,
+          "squashMergeAllowed": null,
+        },
+      },
+      "variables": Object {
+        "name": "repo",
+        "owner": "some",
+      },
+    },
+    "headers": Object {
+      "accept": "application/vnd.github.v3+json",
+      "accept-encoding": "gzip, deflate, br",
+      "authorization": "token 123test",
+      "content-length": "373",
+      "content-type": "application/json",
+      "host": "api.github.com",
+      "user-agent": "RenovateBot/0.0.0-semantic-release (https://github.com/renovatebot/renovate)",
+    },
+    "method": "POST",
+    "url": "https://api.github.com/graphql",
+  },
+  Object {
+    "headers": Object {
+      "accept": "application/vnd.github.v3+json",
+      "accept-encoding": "gzip, deflate, br",
+      "authorization": "token 123test",
+      "host": "api.github.com",
+      "user-agent": "RenovateBot/0.0.0-semantic-release (https://github.com/renovatebot/renovate)",
+    },
+    "method": "GET",
+    "url": "https://api.github.com/repos/some/repo/contents/file.json5",
+  },
+]
+`;
+
 exports[`platform/github/index getJsonFile() throws on errors 1`] = `
 Array [
   Object {
diff --git a/lib/platform/github/index.spec.ts b/lib/platform/github/index.spec.ts
index b988bd51f1795059b9b03aee98341665d06a6948..850d02222110da743d66701d55fb149155028e12 100644
--- a/lib/platform/github/index.spec.ts
+++ b/lib/platform/github/index.spec.ts
@@ -2399,6 +2399,23 @@ describe('platform/github/index', () => {
       expect(res).toEqual(data);
       expect(httpMock.getTrace()).toMatchSnapshot();
     });
+    it('returns file content in json5 format', async () => {
+      const json5Data = `
+        { 
+          // json5 comment
+          foo: 'bar' 
+        }
+      `;
+      const scope = httpMock.scope(githubApiHost);
+      initRepoMock(scope, 'some/repo');
+      await github.initRepo({ repository: 'some/repo', token: 'token' } as any);
+      scope.get('/repos/some/repo/contents/file.json5').reply(200, {
+        content: Buffer.from(json5Data).toString('base64'),
+      });
+      const res = await github.getJsonFile('file.json5');
+      expect(res).toEqual({ foo: 'bar' });
+      expect(httpMock.getTrace()).toMatchSnapshot();
+    });
     it('throws on malformed JSON', async () => {
       const scope = httpMock.scope(githubApiHost);
       initRepoMock(scope, 'some/repo');
diff --git a/lib/platform/github/index.ts b/lib/platform/github/index.ts
index 1ac125cb37c5cebea098f59b2f81595227f663e7..367dbf7456ebd3f0e75ea46629462bdc8f120300 100644
--- a/lib/platform/github/index.ts
+++ b/lib/platform/github/index.ts
@@ -1,6 +1,7 @@
 import URL from 'url';
 import is from '@sindresorhus/is';
 import delay from 'delay';
+import JSON5 from 'json5';
 import { DateTime } from 'luxon';
 import { PlatformId } from '../../constants';
 import {
@@ -166,6 +167,9 @@ export async function getJsonFile(
   repo: string = config.repository
 ): Promise<any | null> {
   const raw = await getRawFile(fileName, repo);
+  if (fileName.endsWith('.json5')) {
+    return JSON5.parse(raw);
+  }
   return JSON.parse(raw);
 }
 
diff --git a/lib/platform/gitlab/__snapshots__/index.spec.ts.snap b/lib/platform/gitlab/__snapshots__/index.spec.ts.snap
index 01d80dece811bc4f02b826583014784d4a1dbcf7..f12f50e8788ef34315f9903f11456037d920101c 100644
--- a/lib/platform/gitlab/__snapshots__/index.spec.ts.snap
+++ b/lib/platform/gitlab/__snapshots__/index.spec.ts.snap
@@ -2214,6 +2214,33 @@ Array [
 ]
 `;
 
+exports[`platform/gitlab/index getJsonFile() returns file content in json5 format 1`] = `
+Array [
+  Object {
+    "headers": Object {
+      "accept": "application/json",
+      "accept-encoding": "gzip, deflate, br",
+      "authorization": "Bearer 123test",
+      "host": "gitlab.com",
+      "user-agent": "RenovateBot/0.0.0-semantic-release (https://github.com/renovatebot/renovate)",
+    },
+    "method": "GET",
+    "url": "https://gitlab.com/api/v4/projects/some%2Frepo",
+  },
+  Object {
+    "headers": Object {
+      "accept": "application/json",
+      "accept-encoding": "gzip, deflate, br",
+      "authorization": "Bearer 123test",
+      "host": "gitlab.com",
+      "user-agent": "RenovateBot/0.0.0-semantic-release (https://github.com/renovatebot/renovate)",
+    },
+    "method": "GET",
+    "url": "https://gitlab.com/api/v4/projects/some%2Frepo/repository/files/dir%2Ffile.json5?ref=HEAD",
+  },
+]
+`;
+
 exports[`platform/gitlab/index getJsonFile() throws on errors 1`] = `
 Array [
   Object {
diff --git a/lib/platform/gitlab/index.spec.ts b/lib/platform/gitlab/index.spec.ts
index 0c553faf91dc280a80567d8a34a26768f3a5cc40..4f3107759acb3f254034400d600ff6a3511c86bd 100644
--- a/lib/platform/gitlab/index.spec.ts
+++ b/lib/platform/gitlab/index.spec.ts
@@ -1917,6 +1917,25 @@ These updates have all been created already. Click a checkbox below to force a r
       expect(res).toEqual(data);
       expect(httpMock.getTrace()).toMatchSnapshot();
     });
+    it('returns file content in json5 format', async () => {
+      const json5Data = `
+        { 
+          // json5 comment
+          foo: 'bar' 
+        }
+        `;
+      const scope = await initRepo();
+      scope
+        .get(
+          '/api/v4/projects/some%2Frepo/repository/files/dir%2Ffile.json5?ref=HEAD'
+        )
+        .reply(200, {
+          content: Buffer.from(json5Data).toString('base64'),
+        });
+      const res = await gitlab.getJsonFile('dir/file.json5');
+      expect(res).toEqual({ foo: 'bar' });
+      expect(httpMock.getTrace()).toMatchSnapshot();
+    });
     it('throws on malformed JSON', async () => {
       const scope = await initRepo();
       scope
diff --git a/lib/platform/gitlab/index.ts b/lib/platform/gitlab/index.ts
index 348372468efb032a73dbde54a4555f94602e2302..f9aabbdfe3a5dfdc61714177924096d3c996b6b3 100644
--- a/lib/platform/gitlab/index.ts
+++ b/lib/platform/gitlab/index.ts
@@ -1,6 +1,7 @@
 import URL from 'url';
 import is from '@sindresorhus/is';
 import delay from 'delay';
+import JSON5 from 'json5';
 import pAll from 'p-all';
 import { lt } from 'semver';
 import { PlatformId } from '../../constants';
@@ -171,6 +172,9 @@ export async function getJsonFile(
   repo: string = config.repository
 ): Promise<any | null> {
   const raw = await getRawFile(fileName, repo);
+  if (fileName.endsWith('.json5')) {
+    return JSON5.parse(raw);
+  }
   return JSON.parse(raw);
 }