diff --git a/splunk/src/main/java/org/apache/calcite/adapter/splunk/search/SplunkConnectionImpl.java b/splunk/src/main/java/org/apache/calcite/adapter/splunk/search/SplunkConnectionImpl.java
index 9664e928b10..e973898ae3b 100644
--- a/splunk/src/main/java/org/apache/calcite/adapter/splunk/search/SplunkConnectionImpl.java
+++ b/splunk/src/main/java/org/apache/calcite/adapter/splunk/search/SplunkConnectionImpl.java
@@ -58,7 +58,7 @@ public class SplunkConnectionImpl implements SplunkConnection {
 
   private static final Pattern SESSION_KEY =
       Pattern.compile(
-          "<response>\\s*<sessionKey>([0-9a-f]+)</sessionKey>\\s*</response>");
+          "<sessionKey>([0-9a-zA-Z^_]+)</sessionKey>");
 
   final URL url;
   final String username;