diff --git a/src/main/java/org/apache/commons/lang3/ThreadUtils.java b/src/main/java/org/apache/commons/lang3/ThreadUtils.java
index a0177ae6e..bbb5d2949 100644
--- a/src/main/java/org/apache/commons/lang3/ThreadUtils.java
+++ b/src/main/java/org/apache/commons/lang3/ThreadUtils.java
@@ -254,7 +254,7 @@ public ThreadUtils() {
      * A predicate for selecting threads.
      */
     //if java minimal version for lang becomes 1.8 extend this interface from java.util.function.Predicate
-    public static interface ThreadPredicate /*extends java.util.function.Predicate<Thread>*/{
+    public interface ThreadPredicate /*extends java.util.function.Predicate<Thread>*/{
 
         /**
          * Evaluates this predicate on the given thread.
@@ -268,7 +268,7 @@ public static interface ThreadPredicate /*extends java.util.function.Predicate<T
      * A predicate for selecting threadgroups.
      */
     //if java minimal version for lang becomes 1.8 extend this interface from java.util.function.Predicate
-    public static interface ThreadGroupPredicate /*extends java.util.function.Predicate<ThreadGroup>*/{
+    public interface ThreadGroupPredicate /*extends java.util.function.Predicate<ThreadGroup>*/{
 
         /**
          * Evaluates this predicate on the given threadgroup.