diff --git a/packages/@uppy/aws-s3-multipart/src/createSignedURL.js b/packages/@uppy/aws-s3-multipart/src/createSignedURL.js
index 593b327b6e..bef07e5b9c 100644
--- a/packages/@uppy/aws-s3-multipart/src/createSignedURL.js
+++ b/packages/@uppy/aws-s3-multipart/src/createSignedURL.js
@@ -76,6 +76,10 @@ async function hash (key, data) {
   return subtle.sign(algorithm, await generateHmacKey(key), ec.encode(data))
 }
 
+function percentEncode(c) {
+  return `%${c.charCodeAt(0).toString(16).toUpperCase()}`
+}
+
 /**
  * @see https://docs.aws.amazon.com/IAM/latest/UserGuide/create-signed-request.html
  * @param {Record<string,string>} param0
@@ -90,7 +94,13 @@ export default async function createSignedURL ({
 }) {
   const Service = 's3'
   const host = `${bucketName}.${Service}.${Region}.amazonaws.com`
-  const CanonicalUri = `/${encodeURI(Key)}`
+  /**
+   * List of char out of `encodeURI()` is taken from ECMAScript spec.
+   * Note that the `/` character is purposefully not included in list below.
+   *
+   * @see https://tc39.es/ecma262/#sec-encodeuri-uri
+   */
+  const CanonicalUri = `/${encodeURI(Key).replace(/[;?:@&=+$,#!'()*]/g, percentEncode)}`
   const payload = 'UNSIGNED-PAYLOAD'
 
   const requestDateTime = new Date().toISOString().replace(/[-:]|\.\d+/g, '') // YYYYMMDDTHHMMSSZ
diff --git a/packages/@uppy/aws-s3-multipart/src/createSignedURL.test.js b/packages/@uppy/aws-s3-multipart/src/createSignedURL.test.js
index cfcb12742c..bb873829eb 100644
--- a/packages/@uppy/aws-s3-multipart/src/createSignedURL.test.js
+++ b/packages/@uppy/aws-s3-multipart/src/createSignedURL.test.js
@@ -47,7 +47,7 @@ describe('createSignedURL', () => {
         Bucket: bucketName,
         Fields: {},
         Key: 'some/key',
-      }, { expiresIn: 900 }))).searchParams.get('X-Amz-Signature'),
+      }), { expiresIn: 900 })).searchParams.get('X-Amz-Signature'),
     )
   })
   it('should be able to sign multipart upload', async () => {
@@ -71,7 +71,43 @@ describe('createSignedURL', () => {
         UploadId: uploadId,
         PartNumber: partNumber,
         Key: 'some/key',
-      }, { expiresIn: 900 }))).searchParams.get('X-Amz-Signature'),
+      }), { expiresIn: 900 })).searchParams.get('X-Amz-Signature'),
     )
   })
+  it('should escape path and query as restricted to RFC 3986', async () => {
+    const client = new S3Client(s3ClientOptions)
+    const partNumber = 99
+    const specialChars = ';?:@&=+$,#!\'()'
+    const uploadId = `Upload${specialChars}Id`
+    // '.*' chars of path should be encoded
+    const Key = `${specialChars}.*/${specialChars}.*.ext`
+    const implResult =
+      await createSignedURL({
+        accountKey: s3ClientOptions.credentials.accessKeyId,
+        accountSecret: s3ClientOptions.credentials.secretAccessKey,
+        sessionToken: s3ClientOptions.credentials.sessionToken,
+        uploadId,
+        partNumber,
+        bucketName,
+        Key,
+        Region: s3ClientOptions.region,
+        expires: 900,
+      })
+    const sdkResult =
+      new URL(
+        await getSignedUrl(client, new UploadPartCommand({
+          Bucket: bucketName,
+          UploadId: uploadId,
+          PartNumber: partNumber,
+          Key,
+        }), { expiresIn: 900 }
+      )
+    )
+    assert.strictEqual(implResult.pathname, sdkResult.pathname)
+
+    const extractUploadId = /([?&])uploadId=([^&]+?)(&|$)/
+    const extractSignature = /([?&])X-Amz-Signature=([^&]+?)(&|$)/
+    assert.strictEqual(implResult.search.match(extractUploadId)[2], sdkResult.search.match(extractUploadId)[2])
+    assert.strictEqual(implResult.search.match(extractSignature)[2], sdkResult.search.match(extractSignature)[2])
+  })
 })