diff --git a/compiler/optimizing/graph_visualizer.cc b/compiler/optimizing/graph_visualizer.cc
index 424a393..7da4f2d 100644
--- a/compiler/optimizing/graph_visualizer.cc
+++ b/compiler/optimizing/graph_visualizer.cc
@@ -270,6 +270,16 @@
         << load_cass->MustGenerateClinitCheck() << std::noboolalpha;
   }
 
+  void VisitCheckCast(HCheckCast* check_cast) OVERRIDE {
+    StartAttributeStream("must_do_null_check") << std::boolalpha
+        << check_cast->MustDoNullCheck() << std::noboolalpha;
+  }
+
+  void VisitInstanceOf(HInstanceOf* instance_of) OVERRIDE {
+    StartAttributeStream("must_do_null_check") << std::boolalpha
+        << instance_of->MustDoNullCheck() << std::noboolalpha;
+  }
+
   bool IsPass(const char* name) {
     return strcmp(pass_name_, name) == 0;
   }
diff --git a/test/486-checker-must-do-null-check/expected.txt b/test/486-checker-must-do-null-check/expected.txt
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/test/486-checker-must-do-null-check/expected.txt
diff --git a/test/486-checker-must-do-null-check/info.txt b/test/486-checker-must-do-null-check/info.txt
new file mode 100644
index 0000000..494ff1c
--- /dev/null
+++ b/test/486-checker-must-do-null-check/info.txt
@@ -0,0 +1 @@
+Verifies MustDoNullCheck() on InstanceOf and CheckCast
diff --git a/test/486-checker-must-do-null-check/src/Main.java b/test/486-checker-must-do-null-check/src/Main.java
new file mode 100644
index 0000000..f285566
--- /dev/null
+++ b/test/486-checker-must-do-null-check/src/Main.java
@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+public class Main {
+  // CHECK-START: void Main.InstanceOfPreChecked(java.lang.Object) instruction_simplifier (after)
+  // CHECK:       InstanceOf must_do_null_check:false
+  public void InstanceOfPreChecked(Object o) throws Exception {
+    o.toString();
+    if (o instanceof Main) {
+      throw new Exception();
+    }
+  }
+
+  // CHECK-START: void Main.InstanceOf(java.lang.Object) instruction_simplifier (after)
+  // CHECK:       InstanceOf must_do_null_check:true
+  public void InstanceOf(Object o) throws Exception {
+    if (o instanceof Main) {
+      throw new Exception();
+    }
+  }
+
+  // CHECK-START: void Main.CheckCastPreChecked(java.lang.Object) instruction_simplifier (after)
+  // CHECK:       CheckCast must_do_null_check:false
+  public void CheckCastPreChecked(Object o) {
+    o.toString();
+    ((Main)o).Bar();
+  }
+
+  // CHECK-START: void Main.CheckCast(java.lang.Object) instruction_simplifier (after)
+  // CHECK:       CheckCast must_do_null_check:true
+  public void CheckCast(Object o) {
+    ((Main)o).Bar();
+  }
+
+  void Bar() {throw new RuntimeException();}
+
+  public static void main(String[] sa) {
+    Main t = new Main();
+  }
+}