diff --git a/tools/sr_mapping/PerM.xml b/tools/sr_mapping/PerM.xml
index 1b787c7d5ca..d0b84ea11fe 100644
--- a/tools/sr_mapping/PerM.xml
+++ b/tools/sr_mapping/PerM.xml
@@ -13,7 +13,7 @@
         #if $s.space == "color"
           "${s.sourceOfRef.index.fields.path}"
         #elif $s.space == "base"
-          "${s.sourceOfRef.index.fields.path"
+          "${s.sourceOfRef.index.fields.path}"
         #end if
       #end if
       #if $s.mate.singleOrPairs == "single":