diff --git a/java-client/src/main/java/org/opensearch/client/transport/aws/AwsSdk2Transport.java b/java-client/src/main/java/org/opensearch/client/transport/aws/AwsSdk2Transport.java
index 26461a8303..f2db2bb7de 100644
--- a/java-client/src/main/java/org/opensearch/client/transport/aws/AwsSdk2Transport.java
+++ b/java-client/src/main/java/org/opensearch/client/transport/aws/AwsSdk2Transport.java
@@ -212,7 +212,7 @@ public <RequestT, ResponseT, ErrorT> ResponseT performRequest(
                 if (cause instanceof RuntimeException) {
                     throw (RuntimeException) cause;
                 }
-                throw new IOException(e);
+                throw new IllegalStateException("unexpected exception type: must be either RuntimeException or IOException", cause);
             } catch (InterruptedException e) {
                 throw new IOException("HttpRequest was interrupted", e);
             }