diff --git a/core/src/main/java/org/acegisecurity/providers/TestingAuthenticationToken.java b/core/src/main/java/org/acegisecurity/providers/TestingAuthenticationToken.java
index fbcafc2702..d54cee41da 100644
--- a/core/src/main/java/org/acegisecurity/providers/TestingAuthenticationToken.java
+++ b/core/src/main/java/org/acegisecurity/providers/TestingAuthenticationToken.java
@@ -47,8 +47,8 @@ public class TestingAuthenticationToken extends AbstractAuthenticationToken {
         this.authorities = authorities;
     }
 
-    private TestingAuthenticationToken() {
-        super();
+    protected TestingAuthenticationToken() {
+        throw new IllegalArgumentException("Cannot use default constructor");
     }
 
     //~ Methods ================================================================
diff --git a/core/src/main/java/org/acegisecurity/providers/UsernamePasswordAuthenticationToken.java b/core/src/main/java/org/acegisecurity/providers/UsernamePasswordAuthenticationToken.java
index 48d035a247..204fa6b743 100644
--- a/core/src/main/java/org/acegisecurity/providers/UsernamePasswordAuthenticationToken.java
+++ b/core/src/main/java/org/acegisecurity/providers/UsernamePasswordAuthenticationToken.java
@@ -56,8 +56,8 @@ public class UsernamePasswordAuthenticationToken
         this.authorities = authorities;
     }
 
-    private UsernamePasswordAuthenticationToken() {
-        super();
+    protected UsernamePasswordAuthenticationToken() {
+        throw new IllegalArgumentException("Cannot use default constructor");
     }
 
     //~ Methods ================================================================