diff --git a/commons/src/main/java/org/archive/util/TestUtils.java b/commons/src/main/java/org/archive/util/TestUtils.java
index 889492a1..a1237483 100644
--- a/commons/src/main/java/org/archive/util/TestUtils.java
+++ b/commons/src/main/java/org/archive/util/TestUtils.java
@@ -127,7 +127,7 @@ public class TestUtils {
                     }
                     cname = cname.replace(File.separatorChar, '.');
                     cname = cname.substring(0, cname.length() - 5);
-                    suite.addTestSuite(Class.forName(cname));
+                    suite.addTestSuite((Class<? extends TestCase>) Class.forName(cname));
                 }
             }
         }