diff --git a/s2a/src/main/java/io/grpc/s2a/handshaker/S2AStub.java b/s2a/src/main/java/io/grpc/s2a/handshaker/S2AStub.java
index bf9b866ef93..ea4fb033a13 100644
--- a/s2a/src/main/java/io/grpc/s2a/handshaker/S2AStub.java
+++ b/s2a/src/main/java/io/grpc/s2a/handshaker/S2AStub.java
@@ -102,8 +102,7 @@ public SessionResp send(SessionReq req) throws IOException, InterruptedException
       if (exception != null) {
         throw new IOException(
             "Received an unexpected response from a host at the S2A's address. The S2A might be"
-                + " unavailable."
-                + exception.getMessage());
+                + " unavailable.", exception);
       } else {
         throw new IOException("Received an unexpected response from a host at the S2A's address.");
       }