diff --git a/handler/proxy_client.go b/handler/proxy_client.go
index beb8032..bee8853 100644
--- a/handler/proxy_client.go
+++ b/handler/proxy_client.go
@@ -56,6 +56,17 @@ func (p *ProxyClient) sign(req *http.Request, service *endpoints.ResolvedEndpoin
 		body = bytes.NewReader(b)
 	}
 
+	// S3 service should not have any escaping applied.
+	// https://github.com/aws/aws-sdk-go/blob/main/aws/signer/v4/v4.go#L467-L470
+        if (service.SigningName == "s3") {
+		p.Signer.DisableURIPathEscaping = true
+
+		// Enable URI escaping for subsequent calls.
+		defer func() {
+			p.Signer.DisableURIPathEscaping = false
+		}()
+	}
+
 	var err error
 	switch service.SigningMethod {
 	case "v4", "s3v4":