diff --git a/springloaded/src/main/java/org/springsource/loaded/TypeRegistry.java b/springloaded/src/main/java/org/springsource/loaded/TypeRegistry.java
index 15d5e52..40e9e7e 100644
--- a/springloaded/src/main/java/org/springsource/loaded/TypeRegistry.java
+++ b/springloaded/src/main/java/org/springsource/loaded/TypeRegistry.java
@@ -597,9 +597,9 @@ public class TypeRegistry {
 	 * If a type is found to come from a jar, we put the package name in here, which should save us looking for types in
 	 * the same package. This does pre-req that there are no split packages.
 	 */
-	private List<String> packagesFound = new ArrayList<String>();
+	private List<String> packagesFound = Collections.synchronizedList(new ArrayList<String>());
 
-	private List<String> packagesNotFound = new ArrayList<String>();
+	private List<String> packagesNotFound = Collections.synchronizedList(new ArrayList<String>());
 
 
 	public static enum CouldBeReloadableDecision {