diff --git a/amazon-kinesis-client-multilang/src/main/java/software/amazon/kinesis/multilang/auth/KclStsAssumeRoleCredentialsProvider.java b/amazon-kinesis-client-multilang/src/main/java/software/amazon/kinesis/multilang/auth/KclStsAssumeRoleCredentialsProvider.java
index ce9de0f5..65c096ae 100644
--- a/amazon-kinesis-client-multilang/src/main/java/software/amazon/kinesis/multilang/auth/KclStsAssumeRoleCredentialsProvider.java
+++ b/amazon-kinesis-client-multilang/src/main/java/software/amazon/kinesis/multilang/auth/KclStsAssumeRoleCredentialsProvider.java
@@ -40,6 +40,9 @@ public class KclStsAssumeRoleCredentialsProvider implements AwsCredentialsProvid
 
     @Override
     public void acceptEndpoint(String serviceEndpoint, String signingRegion) {
+        if (!serviceEndpoint.startsWith("http://") && !serviceEndpoint.startsWith("https://")) {
+            serviceEndpoint = "https://" + serviceEndpoint;
+        }
         stsClientBuilder.endpointOverride(URI.create(serviceEndpoint));
         stsClientBuilder.region(Region.of(signingRegion));
     }