diff --git a/packages/server/modules/blobstorage/index.ts b/packages/server/modules/blobstorage/index.ts
index 72a31eb94d..4936f60000 100644
--- a/packages/server/modules/blobstorage/index.ts
+++ b/packages/server/modules/blobstorage/index.ts
@@ -231,9 +231,12 @@ export const init: SpeckleModule['init'] = async (app) => {
           )
         )
 
-        const status = 400
-        const response = 'Upload request error. The server logs may have more details.'
-        res.status(status).end(response)
+        res.contentType('application/json')
+        res
+          .status(400)
+          .end(
+            '{ "error": "Upload request error. The server logs may have more details." }'
+          )
       })
 
       req.pipe(busboy)
diff --git a/packages/server/modules/core/rest/upload.ts b/packages/server/modules/core/rest/upload.ts
index 2e59c11ab3..c0820168dc 100644
--- a/packages/server/modules/core/rest/upload.ts
+++ b/packages/server/modules/core/rest/upload.ts
@@ -423,7 +423,9 @@ export default (app: Router) => {
         'Error during upload. Error occurred after {elapsedTimeMs}ms. Objects processed before error: {totalObjectsProcessed}. Error: {error}'
       )
       if (!requestDropped)
-        res.status(400).end('Upload request error. The server logs have more details')
+        res
+          .status(400)
+          .end('{"error": "Upload request error. The server logs have more details."}')
       requestDropped = true
     })
 
diff --git a/packages/server/modules/fileuploads/index.ts b/packages/server/modules/fileuploads/index.ts
index ddcebc7b9a..20696b19c6 100644
--- a/packages/server/modules/fileuploads/index.ts
+++ b/packages/server/modules/fileuploads/index.ts
@@ -118,6 +118,7 @@ export const init: SpeckleModule['init'] = async (app, isInitial) => {
               'Error while uploading file.'
             )
           }
+          res.contentType('application/json')
           res.status(response.statusCode).send(body)
         }
       )
diff --git a/packages/server/modules/fileuploads/tests/fileuploads.integration.spec.ts b/packages/server/modules/fileuploads/tests/fileuploads.integration.spec.ts
index 1f72eaf0b2..2bfae6e6f7 100644
--- a/packages/server/modules/fileuploads/tests/fileuploads.integration.spec.ts
+++ b/packages/server/modules/fileuploads/tests/fileuploads.integration.spec.ts
@@ -189,7 +189,9 @@ describe('FileUploads @fileuploads', () => {
         .attach('test.ifc', require.resolve('@/readme.md'), 'test.ifc')
 
       expect(response.statusCode).to.equal(201)
-      expect(response.body).to.deep.equal({})
+      expect(response.headers['content-type']).to.contain('application/json;')
+      expect(response.body.uploadResults).to.have.lengthOf(1)
+      expect(response.body.uploadResults[0].fileName).to.equal('test.ifc')
       const gqlResponse = await sendRequest(userOneToken, {
         query: `query ($streamId: String!) {
           stream(id: $streamId) {
@@ -206,6 +208,9 @@ describe('FileUploads @fileuploads', () => {
       expect(noErrors(gqlResponse))
       expect(gqlResponse.body.data.stream.fileUploads).to.have.lengthOf(1)
       expect(gqlResponse.body.data.stream.fileUploads[0].fileName).to.equal('test.ifc')
+      expect(gqlResponse.body.data.stream.fileUploads[0].id).to.equal(
+        response.body.uploadResults[0].blobId
+      )
 
       //TODO expect subscription notification
     })
@@ -217,7 +222,11 @@ describe('FileUploads @fileuploads', () => {
         .attach('blob1', require.resolve('@/readme.md'), 'test1.ifc')
         .attach('blob2', require.resolve('@/package.json'), 'test2.ifc')
       expect(response.status).to.equal(201)
-      expect(response.body).to.deep.equal({})
+      expect(response.headers['content-type']).to.contain('application/json;')
+      expect(response.body.uploadResults).to.have.lengthOf(2)
+      expect(
+        response.body.uploadResults.map((file: { fileName: string }) => file.fileName)
+      ).to.have.members(['test1.ifc', 'test2.ifc'])
       const gqlResponse = await sendRequest(userOneToken, {
         query: `query ($streamId: String!) {
           stream(id: $streamId) {
@@ -241,6 +250,11 @@ describe('FileUploads @fileuploads', () => {
           (file: { fileName: string }) => file.fileName
         )
       ).to.have.members(['test1.ifc', 'test2.ifc'])
+      expect(
+        gqlResponse.body.data.stream.fileUploads.map((file: { id: string }) => file.id)
+      ).to.have.members(
+        response.body.uploadResults.map((file: { blobId: string }) => file.blobId)
+      )
     })
 
     it('Returns 400 for bad form data', async () => {
@@ -252,6 +266,8 @@ describe('FileUploads @fileuploads', () => {
         .send('--XXX\r\nCon')
 
       expect(response.status).to.equal(400)
+      expect(response.headers['content-type']).to.contain('application/json;')
+      expect(response.body.error).to.contain('Upload request error.')
       const gqlResponse = await sendRequest(userOneToken, {
         query: `query ($streamId: String!) {
           stream(id: $streamId) {
@@ -278,8 +294,11 @@ describe('FileUploads @fileuploads', () => {
         .set('Authorization', `Bearer ${userOneToken}`)
         .attach('toolarge.ifc', Buffer.alloc(114_857_601, 'asdf'), 'toolarge.ifc')
       expect(response.status).to.equal(201)
-
-      expect(response.body).to.deep.equal({})
+      expect(response.headers['content-type']).to.contain('application/json;')
+      expect(response.body.uploadResults).to.have.lengthOf(1)
+      expect(
+        response.body.uploadResults.map((file: { fileName: string }) => file.fileName)
+      ).to.have.members(['toolarge.ifc'])
       const gqlResponse = await sendRequest(userOneToken, {
         query: `query ($streamId: String!) {
           stream(id: $streamId) {
@@ -298,6 +317,9 @@ describe('FileUploads @fileuploads', () => {
         gqlResponse.body.data.stream.fileUploads,
         JSON.stringify(gqlResponse.body.data)
       ).to.have.lengthOf(1)
+      expect(gqlResponse.body.data.stream.fileUploads[0].id).to.equal(
+        response.body.uploadResults[0].blobId
+      )
       //TODO expect no notifications
     })