diff --git a/src/main/java/com/cloudbees/jenkins/plugins/sshagent/exec/ExecRemoteAgent.java b/src/main/java/com/cloudbees/jenkins/plugins/sshagent/exec/ExecRemoteAgent.java
index 3ec9f44..30f889a 100644
--- a/src/main/java/com/cloudbees/jenkins/plugins/sshagent/exec/ExecRemoteAgent.java
+++ b/src/main/java/com/cloudbees/jenkins/plugins/sshagent/exec/ExecRemoteAgent.java
@@ -143,6 +143,7 @@ private Map<String,String> parseAgentEnv(String agentOutput, TaskListener listen
     private String getAgentValue(String agentOutput, String envVar) {
         int pos = agentOutput.indexOf(envVar) + envVar.length() + 1; // +1 for '='
         int end = agentOutput.indexOf(';', pos);
+        if(end < 0) end = agentOutput.length();
         return agentOutput.substring(pos, end);
     }