diff --git a/archaius2-core/src/main/java/com/netflix/archaius/config/AbstractConfig.java b/archaius2-core/src/main/java/com/netflix/archaius/config/AbstractConfig.java
index ca16fb79..709c301d 100644
--- a/archaius2-core/src/main/java/com/netflix/archaius/config/AbstractConfig.java
+++ b/archaius2-core/src/main/java/com/netflix/archaius/config/AbstractConfig.java
@@ -53,7 +53,7 @@ public abstract class AbstractConfig implements Config {
     private final Lookup lookup;
     private volatile Decoder decoder;
     private volatile StrInterpolator interpolator;
-    private String listDelimiter = ",";
+    private volatile String listDelimiter = ",";
     private final String name;
     
     private static final AtomicInteger idCounter = new AtomicInteger();