3 files changed, 3 insertions, 2 deletions
diff --git a/java/com/google/turbine/tree/Pretty.java b/java/com/google/turbine/tree/Pretty.java
index 211774f..6838530 100644
--- a/java/com/google/turbine/tree/Pretty.java
+++ b/java/com/google/turbine/tree/Pretty.java
@@ -34,7 +34,7 @@ import com.google.turbine.tree.Tree.ModUses;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
-import org.checkerframework.checker.nullness.qual.Nullable;
+import org.jspecify.nullness.Nullable;
 
 /** A pretty-printer for {@link Tree}s. */
 public class Pretty implements Tree.Visitor<@Nullable Void, @Nullable Void> {
diff --git a/java/com/google/turbine/tree/Tree.java b/java/com/google/turbine/tree/Tree.java
index 88477a1..7d04312 100644
--- a/java/com/google/turbine/tree/Tree.java
+++ b/java/com/google/turbine/tree/Tree.java
@@ -29,7 +29,7 @@ import java.util.ArrayDeque;
 import java.util.Deque;
 import java.util.Optional;
 import java.util.Set;
-import org.checkerframework.checker.nullness.qual.Nullable;
+import org.jspecify.nullness.Nullable;
 
 /** An AST node. */
 public abstract class Tree {
diff --git a/java/com/google/turbine/tree/package-info.java b/java/com/google/turbine/tree/package-info.java
index e400f40..2803c67 100644
--- a/java/com/google/turbine/tree/package-info.java
+++ b/java/com/google/turbine/tree/package-info.java
@@ -15,4 +15,5 @@
  */
 
 @com.google.errorprone.annotations.CheckReturnValue
+@org.jspecify.nullness.NullMarked
 package com.google.turbine.tree;