diff --git a/runtime/Java/src/org/antlr/v4/runtime/atn/ActionTransition.java b/runtime/Java/src/org/antlr/v4/runtime/atn/ActionTransition.java
index 546fdea35..23162f1b5 100644
--- a/runtime/Java/src/org/antlr/v4/runtime/atn/ActionTransition.java
+++ b/runtime/Java/src/org/antlr/v4/runtime/atn/ActionTransition.java
@@ -31,7 +31,7 @@ package org.antlr.v4.runtime.atn;
 
 import org.antlr.v4.runtime.misc.NotNull;
 
-public class ActionTransition extends Transition {
+public final class ActionTransition extends Transition {
 	public final int ruleIndex;
 	public final int actionIndex;
 	public final boolean isCtxDependent; // e.g., $i ref in action
diff --git a/runtime/Java/src/org/antlr/v4/runtime/atn/AtomTransition.java b/runtime/Java/src/org/antlr/v4/runtime/atn/AtomTransition.java
index 8adb833f3..37c868fc6 100644
--- a/runtime/Java/src/org/antlr/v4/runtime/atn/AtomTransition.java
+++ b/runtime/Java/src/org/antlr/v4/runtime/atn/AtomTransition.java
@@ -33,7 +33,7 @@ import org.antlr.v4.runtime.misc.NotNull;
 import org.antlr.v4.runtime.misc.IntervalSet;
 
 /** TODO: make all transitions sets? no, should remove set edges */
-public class AtomTransition extends Transition {
+public final class AtomTransition extends Transition {
 	/** The token type or character value; or, signifies special label. */
 	public final int label;
 
diff --git a/runtime/Java/src/org/antlr/v4/runtime/atn/EpsilonTransition.java b/runtime/Java/src/org/antlr/v4/runtime/atn/EpsilonTransition.java
index 8678ecf1a..3ff8a97a0 100644
--- a/runtime/Java/src/org/antlr/v4/runtime/atn/EpsilonTransition.java
+++ b/runtime/Java/src/org/antlr/v4/runtime/atn/EpsilonTransition.java
@@ -31,7 +31,7 @@ package org.antlr.v4.runtime.atn;
 
 import org.antlr.v4.runtime.misc.NotNull;
 
-public class EpsilonTransition extends Transition {
+public final class EpsilonTransition extends Transition {
 	public EpsilonTransition(@NotNull ATNState target) { super(target); }
 
 	@Override
diff --git a/runtime/Java/src/org/antlr/v4/runtime/atn/NotSetTransition.java b/runtime/Java/src/org/antlr/v4/runtime/atn/NotSetTransition.java
index 11e060283..5f66abec3 100644
--- a/runtime/Java/src/org/antlr/v4/runtime/atn/NotSetTransition.java
+++ b/runtime/Java/src/org/antlr/v4/runtime/atn/NotSetTransition.java
@@ -33,7 +33,7 @@ import org.antlr.v4.runtime.misc.IntervalSet;
 import org.antlr.v4.runtime.misc.NotNull;
 import org.antlr.v4.runtime.misc.Nullable;
 
-public class NotSetTransition extends SetTransition {
+public final class NotSetTransition extends SetTransition {
 	public NotSetTransition(@NotNull ATNState target, @Nullable IntervalSet set) {
 		super(target, set);
 	}
diff --git a/runtime/Java/src/org/antlr/v4/runtime/atn/PredicateTransition.java b/runtime/Java/src/org/antlr/v4/runtime/atn/PredicateTransition.java
index 32b389b2f..4e6d17bcc 100644
--- a/runtime/Java/src/org/antlr/v4/runtime/atn/PredicateTransition.java
+++ b/runtime/Java/src/org/antlr/v4/runtime/atn/PredicateTransition.java
@@ -37,7 +37,7 @@ import org.antlr.v4.runtime.misc.NotNull;
  *  may have to combine a bunch of them as it collects predicates from
  *  multiple ATN configurations into a single DFA state.
  */
-public class PredicateTransition extends Transition {
+public final class PredicateTransition extends Transition {
 	public final int ruleIndex;
 	public final int predIndex;
 	public final boolean isCtxDependent;  // e.g., $i ref in pred
diff --git a/runtime/Java/src/org/antlr/v4/runtime/atn/RangeTransition.java b/runtime/Java/src/org/antlr/v4/runtime/atn/RangeTransition.java
index b2212c3f7..988b36640 100644
--- a/runtime/Java/src/org/antlr/v4/runtime/atn/RangeTransition.java
+++ b/runtime/Java/src/org/antlr/v4/runtime/atn/RangeTransition.java
@@ -32,7 +32,7 @@ package org.antlr.v4.runtime.atn;
 import org.antlr.v4.runtime.misc.NotNull;
 import org.antlr.v4.runtime.misc.IntervalSet;
 
-public class RangeTransition extends Transition {
+public final class RangeTransition extends Transition {
 	public final int from;
 	public final int to;
 
diff --git a/runtime/Java/src/org/antlr/v4/runtime/atn/RuleTransition.java b/runtime/Java/src/org/antlr/v4/runtime/atn/RuleTransition.java
index 4c1128083..b7f4cf10f 100644
--- a/runtime/Java/src/org/antlr/v4/runtime/atn/RuleTransition.java
+++ b/runtime/Java/src/org/antlr/v4/runtime/atn/RuleTransition.java
@@ -32,7 +32,7 @@ package org.antlr.v4.runtime.atn;
 import org.antlr.v4.runtime.misc.NotNull;
 
 /** */
-public class RuleTransition extends Transition {
+public final class RuleTransition extends Transition {
 	/** Ptr to the rule definition object for this rule ref */
 	public final int ruleIndex;     // no Rule object at runtime
 
diff --git a/runtime/Java/src/org/antlr/v4/runtime/atn/WildcardTransition.java b/runtime/Java/src/org/antlr/v4/runtime/atn/WildcardTransition.java
index f5b175ef7..22c8edd97 100644
--- a/runtime/Java/src/org/antlr/v4/runtime/atn/WildcardTransition.java
+++ b/runtime/Java/src/org/antlr/v4/runtime/atn/WildcardTransition.java
@@ -31,7 +31,7 @@ package org.antlr.v4.runtime.atn;
 
 import org.antlr.v4.runtime.misc.NotNull;
 
-public class WildcardTransition extends Transition {
+public final class WildcardTransition extends Transition {
 	public WildcardTransition(@NotNull ATNState target) { super(target); }
 
 	@Override