diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/filter/RevFilter.java b/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/filter/RevFilter.java
index 378c90699..8b45a312e 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/filter/RevFilter.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/filter/RevFilter.java
@@ -94,7 +94,9 @@ import org.eclipse.jgit.revwalk.RevWalk;
  */
 public abstract class RevFilter {
 	/** Default filter that always returns true (thread safe). */
-	public static final RevFilter ALL = new RevFilter() {
+	public static final RevFilter ALL = new AllFilter();
+
+	private static final class AllFilter extends RevFilter {
 		@Override
 		public boolean include(final RevWalk walker, final RevCommit c) {
 			return true;
@@ -109,10 +111,12 @@ public abstract class RevFilter {
 		public String toString() {
 			return "ALL";
 		}
-	};
+	}
 
 	/** Default filter that always returns false (thread safe). */
-	public static final RevFilter NONE = new RevFilter() {
+	public static final RevFilter NONE = new NoneFilter();
+
+	private static final class NoneFilter extends RevFilter {
 		@Override
 		public boolean include(final RevWalk walker, final RevCommit c) {
 			return false;
@@ -127,10 +131,12 @@ public abstract class RevFilter {
 		public String toString() {
 			return "NONE";
 		}
-	};
+	}
 
 	/** Excludes commits with more than one parent (thread safe). */
-	public static final RevFilter NO_MERGES = new RevFilter() {
+	public static final RevFilter NO_MERGES = new NoMergesFilter();
+
+	private static final class NoMergesFilter extends RevFilter {
 		@Override
 		public boolean include(final RevWalk walker, final RevCommit c) {
 			return c.getParentCount() < 2;
@@ -145,7 +151,7 @@ public abstract class RevFilter {
 		public String toString() {
 			return "NO_MERGES";
 		}
-	};
+	}
 
 	/**
 	 * Selects only merge bases of the starting points (thread safe).
@@ -155,7 +161,9 @@ public abstract class RevFilter {
 	 * information beyond the arguments is necessary to determine if the
 	 * supplied commit is a merge base.
 	 */
-	public static final RevFilter MERGE_BASE = new RevFilter() {
+	public static final RevFilter MERGE_BASE = new MergeBaseFilter();
+
+	private static final class MergeBaseFilter extends RevFilter {
 		@Override
 		public boolean include(final RevWalk walker, final RevCommit c) {
 			throw new UnsupportedOperationException(JGitText.get().cannotBeCombined);
@@ -170,7 +178,7 @@ public abstract class RevFilter {
 		public String toString() {
 			return "MERGE_BASE";
 		}
-	};
+	}
 
 	/**
 	 * Create a new filter that does the opposite of this filter.
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/treewalk/filter/TreeFilter.java b/org.eclipse.jgit/src/org/eclipse/jgit/treewalk/filter/TreeFilter.java
index 50421fe7a..9348afc8a 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/treewalk/filter/TreeFilter.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/treewalk/filter/TreeFilter.java
@@ -84,7 +84,9 @@ import org.eclipse.jgit.treewalk.TreeWalk;
  */
 public abstract class TreeFilter {
 	/** Selects all tree entries. */
-	public static final TreeFilter ALL = new TreeFilter() {
+	public static final TreeFilter ALL = new AllFilter();
+
+	private static final class AllFilter extends TreeFilter {
 		@Override
 		public boolean include(final TreeWalk walker) {
 			return true;
@@ -104,7 +106,7 @@ public abstract class TreeFilter {
 		public String toString() {
 			return "ALL";
 		}
-	};
+	}
 
 	/**
 	 * Selects only tree entries which differ between at least 2 trees.
@@ -119,7 +121,9 @@ public abstract class TreeFilter {
 	 * against the single tree it was actually given. Applications may wish to
 	 * treat such a difference as "all names added".
 	 */
-	public static final TreeFilter ANY_DIFF = new TreeFilter() {
+	public static final TreeFilter ANY_DIFF = new AnyDiffFilter();
+
+	private static final class AnyDiffFilter extends TreeFilter {
 		private static final int baseTree = 0;
 
 		@Override
@@ -149,7 +153,7 @@ public abstract class TreeFilter {
 		public String toString() {
 			return "ANY_DIFF";
 		}
-	};
+	}
 
 	/**
 	 * Create a new filter that does the opposite of this filter.