diff --git a/dev/core/src/com/google/gwt/dev/jjs/impl/Pruner.java b/dev/core/src/com/google/gwt/dev/jjs/impl/Pruner.java
index 5192781..f1b4fac 100644
--- a/dev/core/src/com/google/gwt/dev/jjs/impl/Pruner.java
+++ b/dev/core/src/com/google/gwt/dev/jjs/impl/Pruner.java
@@ -89,7 +89,8 @@
    * Remove assignments to pruned fields, locals and params. Nullify the return
    * type of methods declared to return a globally uninstantiable type. Replace
    * references to pruned variables and methods by references to the null field
-   * and null method, and drop assignments to pruned variables.
+   * and null method, assignments to pruned variables, and nullify the type of
+   * variable whose type is a pruned type.
    */
   private class CleanupRefsVisitor extends JModVisitorWithTemporaryVariableCreation {
     private final Stack<JExpression> lValues = new Stack<JExpression>();
@@ -237,6 +238,15 @@
     }
 
     @Override
+    public void exit(JVariable x, Context ctx) {
+      JType type = x.getType();
+      if (type instanceof JReferenceType &&
+          !program.typeOracle.isInstantiatedType((JReferenceType) type)) {
+        x.setType(program.getTypeNull());
+      }
+    }
+
+    @Override
     public boolean visit(JBinaryOperation x, Context ctx) {
       if (x.getOp() == JBinaryOperator.ASG) {
         lValues.push(x.getLhs());
diff --git a/dev/core/test/com/google/gwt/dev/jjs/impl/PrunerTest.java b/dev/core/test/com/google/gwt/dev/jjs/impl/PrunerTest.java
index 6e71b96..f74d570 100644
--- a/dev/core/test/com/google/gwt/dev/jjs/impl/PrunerTest.java
+++ b/dev/core/test/com/google/gwt/dev/jjs/impl/PrunerTest.java
@@ -198,6 +198,15 @@
     assertNotNull(result.findClass("EntryPoint$JsProtoImpl2"));
   }
 
+  public void testCleanupVariableOfNonReferencedType() throws Exception {
+    runDeadCodeElimination = false;
+    addSnippetClassDecl("static class A {}");
+    addSnippetClassDecl("static boolean fun(A a) { return a == null; }");
+    Result result = optimize("void", "fun(null);");
+    assertNull(result.findClass("EntryPoint$A"));
+    assertEquals("static boolean fun(null a);\n", result.findMethod("fun").toString());
+  }
+
   /**
    * Test for issue 2478.
    */