diff --git a/TestON/JenkinsFile/JenkinsCommonFuncs.groovy b/TestON/JenkinsFile/JenkinsCommonFuncs.groovy
index d6ab3b3..1eb1386 100644
--- a/TestON/JenkinsFile/JenkinsCommonFuncs.groovy
+++ b/TestON/JenkinsFile/JenkinsCommonFuncs.groovy
@@ -36,7 +36,7 @@
   generalFuncs.initBasicVars();
 }
 def additionalInitForSR( branch ){
-  testMachine = testMachine.insert( testMachine.length-1, fabricOn( branch ) )
+  testMachine = ( ( new StringBuilder( testmachine ) ).insert( testMachine.length-1, fabricOn( branch ) ) ).toString()
   print testMachine
 }
 def fabricOn( branch ){