diff --git a/runtime/Java/src/org/antlr/v4/runtime/atn/PredictionContext.java b/runtime/Java/src/org/antlr/v4/runtime/atn/PredictionContext.java
index e6d89b0f6..1ddcf5d2d 100644
--- a/runtime/Java/src/org/antlr/v4/runtime/atn/PredictionContext.java
+++ b/runtime/Java/src/org/antlr/v4/runtime/atn/PredictionContext.java
@@ -40,13 +40,13 @@ import org.antlr.v4.runtime.misc.Nullable;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
+import java.util.Comparator;
 import java.util.HashMap;
 import java.util.IdentityHashMap;
 import java.util.List;
 import java.util.Map;
 
-public abstract class PredictionContext implements Comparable<PredictionContext> // to sort node lists by id
-{
+public abstract class PredictionContext {
 	/**
 	 * Represents {@code $} in local context prediction, which means wildcard.
 	 * {@code *+x = *}.
@@ -130,11 +130,6 @@ public abstract class PredictionContext implements Comparable<PredictionContext>
 		return getReturnState(size() - 1) == EMPTY_RETURN_STATE;
 	}
 
-	@Override
-	public int compareTo(PredictionContext o) { // used for toDotString to print nodes in order
-		return id - o.id;
-	}
-
 	@Override
 	public final int hashCode() {
 		return cachedHashCode;
@@ -550,7 +545,12 @@ public abstract class PredictionContext implements Comparable<PredictionContext>
 		buf.append("rankdir=LR;\n");
 
 		List<PredictionContext> nodes = getAllContextNodes(context);
-		Collections.sort(nodes);
+		Collections.sort(nodes, new Comparator<PredictionContext>() {
+			@Override
+			public int compare(PredictionContext o1, PredictionContext o2) {
+				return o1.id - o2.id;
+			}
+		});
 
 		for (PredictionContext current : nodes) {
 			if ( current instanceof SingletonPredictionContext ) {