diff --git a/java/src/org/apache/xml/resolver/Catalog.java b/java/src/org/apache/xml/resolver/Catalog.java
index bc4474e..8ac28c0 100644
--- a/java/src/org/apache/xml/resolver/Catalog.java
+++ b/java/src/org/apache/xml/resolver/Catalog.java
@@ -923,7 +923,11 @@ public class Catalog {
       String value = entry.getEntryArg(0);
       URL newbase = null;
 
-      catalogManager.debug.message(5, "BASE CUR", base.toString());
+      if (base == null) {
+	catalogManager.debug.message(5, "BASE CUR", "null");
+      } else {
+	catalogManager.debug.message(5, "BASE CUR", base.toString());
+      }
       catalogManager.debug.message(4, "BASE STR", value);
 
       try {