diff --git a/otoroshi/app/auth/saml/SAMLClient.scala b/otoroshi/app/auth/saml/SAMLClient.scala
index bb5009430a..53a0c25122 100644
--- a/otoroshi/app/auth/saml/SAMLClient.scala
+++ b/otoroshi/app/auth/saml/SAMLClient.scala
@@ -55,6 +55,8 @@ import scala.concurrent.{ExecutionContext, Future}
 import scala.jdk.CollectionConverters.{asScalaBufferConverter, asScalaSetConverter}
 import scala.util.Try
 
+import java.util.zip.Deflater
+
 case class SAMLModule(authConfig: SamlAuthModuleConfig) extends AuthModule {
 
   import SAMLModule._
@@ -777,10 +779,18 @@ object SAMLModule {
     nameIDPolicy.setFormat(samlConfig.nameIDFormat.value)
     request.setNameIDPolicy(nameIDPolicy)
 
+    request.setID("z" + UUID.randomUUID().toString)
+
     val issuer = buildObject(Issuer.DEFAULT_ELEMENT_NAME).asInstanceOf[Issuer]
     issuer.setValue(samlConfig.issuer)
     request.setIssuer(issuer)
 
+    val subject = buildObject(Subject.DEFAULT_ELEMENT_NAME).asInstanceOf[Subject]
+    val nameID = buildObject(NameID.DEFAULT_ELEMENT_NAME).asInstanceOf[NameID]
+    nameID.setValue("z" + UUID.randomUUID().toString)
+    subject.setNameID(nameID)
+    request.setSubject(subject)
+
     request.setIssueInstant(Instant.now())
 
     signSAMLObject(env, samlConfig, request.asInstanceOf[RequestAbstractType]).map {
@@ -822,8 +832,10 @@ object SAMLModule {
     val dom          = marshaller.marshall(request)
 
     XMLHelper.writeNode(dom, stringWriter)
+    val body = stringWriter.toString
+    val deflatedBody = doDeflate(body.getBytes(StandardCharsets.UTF_8))
 
-    org.apache.commons.codec.binary.Base64.encodeBase64String(stringWriter.toString.getBytes(StandardCharsets.UTF_8))
+    org.apache.commons.codec.binary.Base64.encodeBase64URLSafeString(deflatedBody)
   }
 
   def decodeAndValidateSamlResponse(
@@ -1013,6 +1025,21 @@ object SAMLModule {
       }
   }
 
+  def doDeflate(dataBytes: Array[Byte]): Array[Byte] = {
+    var compBufSize = 655316
+    if (compBufSize < dataBytes.length + 5) {
+      compBufSize = dataBytes.length + 5
+    }
+    val compBuf = new Array[Byte](compBufSize)
+    val compresser = new Deflater(9, true)
+    compresser.setInput(dataBytes)
+    compresser.finish
+    val compressedDataLength = compresser.deflate(compBuf)
+    val compressedData = new Array[Byte](compressedDataLength)
+    System.arraycopy(compBuf, 0, compressedData, 0, compressedDataLength)
+    compressedData
+  }
+
   def decodeAssertionWithCertificate(response: Response, certificate: BasicX509Credential): Future[Unit] = {
     val resolverChain = new util.ArrayList[KeyInfoCredentialResolver]()
     resolverChain.add(new StaticKeyInfoCredentialResolver(certificate))