diff --git a/dev/core/src/com/google/gwt/dev/jjs/impl/ControlFlowAnalyzer.java b/dev/core/src/com/google/gwt/dev/jjs/impl/ControlFlowAnalyzer.java
index cbc44f4..aa4e865 100644
--- a/dev/core/src/com/google/gwt/dev/jjs/impl/ControlFlowAnalyzer.java
+++ b/dev/core/src/com/google/gwt/dev/jjs/impl/ControlFlowAnalyzer.java
@@ -376,7 +376,7 @@
         }
       }
 
-      if (argsToRescueIfParameterRead == null || method.canBePolymorphic()
+      if (argumentsToRescueIfParameterRead == null || method.canBePolymorphic()
           || call instanceof JsniMethodRef) {
         return true;
       }
@@ -619,7 +619,7 @@
         if (dependencyRecorder != null) {
           curMethodStack.remove(curMethodStack.size() - 1);
         }
-        if (method.isJsniMethod()) {
+        if (method.isJsniMethod() || method.canBeImplementedExternally()) {
           // Returning from this method passes a value from JavaScript into Java.
           maybeRescueJavaScriptObjectPassingIntoJava(method.getType());
         }
@@ -627,6 +627,9 @@
           for (JParameter param : method.getParams()) {
             // Parameters in JsExport, JsType, JsFunction methods should not be pruned in order to
             // keep the API intact.
+            if (method.canBeReferencedExternally()) {
+              maybeRescueJavaScriptObjectPassingIntoJava(param.getType());
+            }
             rescue(param);
             if (param.isVarargs()) {
               assert method.isJsMethodVarargs();
@@ -720,47 +723,54 @@
         // Already rescued.
         return;
       }
-      membersToRescueIfTypeIsInstantiated.remove(var);
-      if (var == getClassField) {
-        rescueClassLiteralsIfGetClassIsLive();
-      }
 
-      if (isStaticFieldInitializedToLiteral(var)) {
-        /*
-         * Rescue literal initializers when the field is rescued, not when
-         * the static initializer runs. This allows fields initialized to
-         * string literals to only need the string literals when the field
-         * itself becomes live.
-         *
-         * NOTE: needs to be in sync with {@link JTypeOracle.CheckClinitVistior}.
-         */
-        accept(((JField) var).getLiteralInitializer());
-      } else if (var instanceof JField
-          && (program.getTypeClassLiteralHolder().equals(((JField) var).getEnclosingType()))) {
-        /*
-         * Rescue just slightly less than what would normally be rescued for
-         * a field reference to the literal's field. Rescue the field
-         * itself, and its initializer, but do NOT rescue the whole
-         * enclosing class. That would pull in the clinit of that class,
-         * which has initializers for all the class literals, which in turn
-         * have all of the strings of all of the class names.
-         *
-         * This work is done in rescue() to allow JSNI references to class
-         * literals (via the @Foo::class syntax) to correctly rescue class
-         * literal initializers.
-         *
-         * TODO: Model ClassLiteral access a different way to avoid special
-         * handling. See
-         *  Pruner.transformToNullFieldRef()/transformToNullMethodCall().
-         */
+      if (var instanceof JField) {
         JField field = (JField) var;
-        accept(field.getInitializer());
-        referencedTypes.add(field.getEnclosingType());
-        liveFieldsAndMethods.add(field.getEnclosingType().getClinitMethod());
-      } else if (argsToRescueIfParameterRead != null && var instanceof JParameter) {
-        List<JExpression> list = argsToRescueIfParameterRead.removeAll(var);
-        for (JExpression arg : list) {
-          this.accept(arg);
+
+        membersToRescueIfTypeIsInstantiated.remove(field);
+
+        if (field.canBeReferencedExternally() || field.canBeImplementedExternally()) {
+          maybeRescueJavaScriptObjectPassingIntoJava(field.getType());
+        }
+
+        if (field == getClassField) {
+          rescueClassLiteralsIfGetClassIsLive();
+        }
+
+        if (isStaticFieldInitializedToLiteral(field)) {
+          /*
+           * Rescue literal initializers when the field is rescued, not when
+           * the static initializer runs. This allows fields initialized to
+           * string literals to only need the string literals when the field
+           * itself becomes live.
+           *
+           * NOTE: needs to be in sync with {@link JTypeOracle.CheckClinitVistior}.
+           */
+          accept(field.getLiteralInitializer());
+        } else if (program.getTypeClassLiteralHolder().equals(field.getEnclosingType())) {
+          /*
+           * Rescue just slightly less than what would normally be rescued for
+           * a field reference to the literal's field. Rescue the field
+           * itself, and its initializer, but do NOT rescue the whole
+           * enclosing class. That would pull in the clinit of that class,
+           * which has initializers for all the class literals, which in turn
+           * have all of the strings of all of the class names.
+           *
+           * This work is done in rescue() to allow JSNI references to class
+           * literals (via the @Foo::class syntax) to correctly rescue class
+           * literal initializers.
+           *
+           * TODO: Model ClassLiteral access a different way to avoid special
+           * handling. See
+           *  Pruner.transformToNullFieldRef()/transformToNullMethodCall().
+           */
+          accept(field.getInitializer());
+          referencedTypes.add(field.getEnclosingType());
+          liveFieldsAndMethods.add(field.getEnclosingType().getClinitMethod());
+        }
+      } else if (var instanceof JParameter && argumentsToRescueIfParameterRead != null) {
+        for (JExpression arg : argumentsToRescueIfParameterRead.removeAll(var)) {
+          accept(arg);
         }
       }
     }
@@ -786,7 +796,7 @@
           this.accept(arg);
           continue;
         }
-        argsToRescueIfParameterRead.put(param, arg);
+        argumentsToRescueIfParameterRead.put(param, arg);
       }
       // Visit any "extra" arguments that exceed the param list.
       for (int c = args.size(); i < c; ++i) {
@@ -894,7 +904,7 @@
    * read, we will need to rescue the associated arguments. See comments in
    * {@link #rescueArgumentsIfParametersCanBeRead}.
    */
-  private ListMultimap<JParameter, JExpression> argsToRescueIfParameterRead;
+  private ListMultimap<JParameter, JExpression> argumentsToRescueIfParameterRead;
 
   private final JMethod asyncFragmentOnLoad;
 
@@ -940,9 +950,9 @@
     liveStrings = Sets.newHashSet(cfa.liveStrings);
     membersToRescueIfTypeIsInstantiated =
         Sets.newHashSet(cfa.membersToRescueIfTypeIsInstantiated);
-    if (cfa.argsToRescueIfParameterRead != null) {
-      argsToRescueIfParameterRead =
-          ArrayListMultimap.create(cfa.argsToRescueIfParameterRead);
+    if (cfa.argumentsToRescueIfParameterRead != null) {
+      argumentsToRescueIfParameterRead =
+          ArrayListMultimap.create(cfa.argumentsToRescueIfParameterRead);
     }
     rescuer = new RescueVisitor();
   }
@@ -1001,8 +1011,8 @@
   }
 
   public void setForPruning() {
-    assert argsToRescueIfParameterRead == null;
-    argsToRescueIfParameterRead = ArrayListMultimap.create();
+    assert argumentsToRescueIfParameterRead == null;
+    argumentsToRescueIfParameterRead = ArrayListMultimap.create();
   }
 
   /**
diff --git a/dev/core/test/com/google/gwt/dev/jjs/impl/ControlFlowAnalyzerTest.java b/dev/core/test/com/google/gwt/dev/jjs/impl/ControlFlowAnalyzerTest.java
index deaa8f5..2f26cb5 100644
--- a/dev/core/test/com/google/gwt/dev/jjs/impl/ControlFlowAnalyzerTest.java
+++ b/dev/core/test/com/google/gwt/dev/jjs/impl/ControlFlowAnalyzerTest.java
@@ -105,87 +105,27 @@
    * circumstances where values can pass from JS into Java.
    */
   public void testRescueJavaScriptObjectFromJsni() throws Exception {
-      sourceOracle.addOrReplace(new MockJavaResource("test.JsoIntf") {
-      @Override
-      public CharSequence getContent() {
-        return Joiner.on("\n").join(
-            "package test;",
-            "import com.google.gwt.core.client.JavaScriptObject;",
-            "public interface JsoIntf {",
-            "  public int getAny();",
-            "}");
-      }
-    });
-
-      sourceOracle.addOrReplace(new MockJavaResource("test.UpRefIntf") {
-      @Override
-      public CharSequence getContent() {
-        return Joiner.on("\n").join(
-            "package test;",
-            "import com.google.gwt.core.client.JavaScriptObject;",
-            "public interface UpRefIntf {",
-            "  public int getFoo();",
-            "}");
-      }
-    });
-
-     sourceOracle.addOrReplace(new MockJavaResource("test.NonImplementor") {
-      @Override
-      public CharSequence getContent() {
-        return Joiner.on("\n").join(
-            "package test;",
-            "import com.google.gwt.core.client.JavaScriptObject;",
-            "public class NonImplementor extends JavaScriptObject {",
-            "  protected NonImplementor() {}",
-            "  final public native int getFoo() /*-{ return 0; }-*/;",
-            "}");
-      }
-    });
-
-     sourceOracle.addOrReplace(new MockJavaResource("test.VirtualUpRef") {
-      @Override
-      public CharSequence getContent() {
-        return Joiner.on("\n").join(
-            "package test;",
-            "import com.google.gwt.core.client.JavaScriptObject;",
-            "final public class VirtualUpRef extends NonImplementor implements UpRefIntf {",
-            "  protected VirtualUpRef() {}",
-            "  public static native VirtualUpRef create() /*-{ return  {}; }-*/;",
-            "}");
-      }
-    });
-
-    sourceOracle.addOrReplace(new MockJavaResource("test.SingleJso") {
-      @Override
-      public CharSequence getContent() {
-        return Joiner.on("\n").join(
-            "package test;",
-            "import com.google.gwt.core.client.JavaScriptObject;",
-            "final public class SingleJso extends JavaScriptObject implements JsoIntf {",
-            "  protected SingleJso() {}",
-            "  public native int getAny() /*-{ return 1; }-*/;",
-            "  public static native JsoIntf returnsJsoIntf() /*-{ return {}; }-*/;",
-            "  public static native SingleJso returnsJso() /*-{ return {}; }-*/;",
-            "}");
-      }
-    });
-
-    sourceOracle.addOrReplace(new MockJavaResource("test.Foo") {
-      @Override
-      public CharSequence getContent() {
-        return Joiner.on("\n").join(
-            "package test;",
-            "import com.google.gwt.core.client.JavaScriptObject;",
-            "public class Foo {",
-            "  public static native JavaScriptObject returnsJso() /*-{ return {}; }-*/;",
-            "  public static native void assignsJsoField() /*-{ @test.Foo::jsoField = {}; }-*/;",
-            "  public static native void readsJsoField() /*-{ var x = @test.Foo::jsoField; }-*/;",
-            "  public static native void passesJsoParam() /*-{ @test.Foo::calledFromJsni(Lcom/google/gwt/core/client/JavaScriptObject;)({}); }-*/;",
-            "  private static JavaScriptObject jsoField = null;",
-            "  private static void calledFromJsni(JavaScriptObject arg) { }",
-            "}");
-      }
-    });
+    addJsoResources();
+    addOrReplaceResource("test.VirtualUpRef",
+        "package test;",
+        "import com.google.gwt.core.client.JavaScriptObject;",
+        "final public class VirtualUpRef extends NonImplementor implements UpRefIntf {",
+        "  protected VirtualUpRef() {}",
+        "  public static native VirtualUpRef create() /*-{ return  {}; }-*/;",
+        "}");
+    addOrReplaceResource("test.Foo",
+        "package test;",
+        "import com.google.gwt.core.client.JavaScriptObject;",
+        "public class Foo {",
+        "  public static native JavaScriptObject returnsJso() /*-{ return {}; }-*/;",
+        "  public static native void assignsJsoField() /*-{ @test.Foo::jsoField = {}; }-*/;",
+        "  public static native void readsJsoField() /*-{ var x = @test.Foo::jsoField; }-*/;",
+        "  public static native void passesJsoParam() /*-{ @test.Foo::calledFromJsni(Lcom/google/gwt/core/client/JavaScriptObject;)({}); }-*/;",
+        "  private static JavaScriptObject jsoField = null;",
+        "  private static void calledFromJsni(JavaScriptObject arg) { }",
+        "  public static native JsoIntf returnsJsoIntf() /*-{ return {}; }-*/;",
+        "  public static native SingleJso returnsSingleJso() /*-{ return {}; }-*/;",
+        "}");
     addSnippetImport("test.Foo");
 
     analyzeSnippet("").assertOnlyInstantiatedTypes(Empty.STRINGS);
@@ -207,11 +147,11 @@
         "JavaScriptObject", "Object");
 
     // Returning a JSO subType instantiates it
-    analyzeSnippet("SingleJso.returnsJso();").assertOnlyInstantiatedTypes(
+    analyzeSnippet("Foo.returnsSingleJso();").assertOnlyInstantiatedTypes(
         "SingleJso", "JavaScriptObject", "Object", "JsoIntf");
 
     // Returning a JSO SingleJsoImpl instantiates it and the implementor
-    analyzeSnippet("SingleJso.returnsJsoIntf();").assertOnlyInstantiatedTypes(
+    analyzeSnippet("Foo.returnsJsoIntf();").assertOnlyInstantiatedTypes(
         "SingleJso", "JavaScriptObject", "Object", "JsoIntf");
 
     // A virtual upref should still be rescued
@@ -235,17 +175,11 @@
    * instantiated in JSNI.
    */
   public void testRescueArraysFromJSNI() throws Exception {
-    sourceOracle.addOrReplace(new MockJavaResource("test.Foo") {
-      @Override
-      public CharSequence getContent() {
-        return Joiner.on("\n").join(
-            "package test;",
-            "public class Foo {",
-            "  public static native int[] create_array() /*-{ return {}; }-*/;",
-            "  public static native int[][] create_2d_array() /*-{ return {}; }-*/;",
-            "}");
-      }
-    });
+    addOrReplaceResource("test.Foo",
+        "package test;", "public class Foo {",
+        "  public static native int[] create_array() /*-{ return {}; }-*/;",
+        "  public static native int[][] create_2d_array() /*-{ return {}; }-*/;",
+        "}");
     addSnippetImport("test.Foo");
 
     analyzeSnippet("").assertOnlyInstantiatedTypes(Empty.STRINGS);
@@ -259,6 +193,133 @@
         "int[][]", "Object[]", "Object");
   }
 
+  public void testRescueJavaScriptObjectReturnedFromExternallyImplementedMethod() throws Exception {
+    addJsoResources();
+    addSnippetImport("test.Test");
+
+    addOrReplaceResource("test.Test",
+        "package test;",
+        "import jsinterop.annotations.JsMethod;",
+        "public class Test {",
+        "  @JsMethod",
+        "  public static native JsoIntf returnsJsoInterface();",
+        "}"
+    );
+    analyzeSnippet("Test.returnsJsoInterface();").assertOnlyInstantiatedTypes(
+        "JsoIntf", "SingleJso", "JavaScriptObject", "Object");
+
+    addOrReplaceResource("test.Test",
+        "package test;",
+        "import jsinterop.annotations.JsMethod;",
+        "public class Test {",
+        "  @JsMethod",
+        "  public static native SingleJso returnsJso();",
+        "}"
+    );
+    analyzeSnippet("Test.returnsJso();").assertOnlyInstantiatedTypes(
+        "JsoIntf", "SingleJso", "JavaScriptObject", "Object");
+  }
+
+  public void testRescueJavaScriptObjectParameterToJsInteropEntryPoint() throws Exception {
+    addJsoResources();
+    addSnippetImport("test.Test");
+
+    addOrReplaceResource("test.Test",
+        "package test;",
+        "import jsinterop.annotations.JsMethod;",
+        "public class Test {",
+        "  public static void receivesJsoInterface(JsoIntf i) {};",
+        "}"
+    );
+    analyzeSnippet("Test.receivesJsoInterface(null);").assertOnlyInstantiatedTypes(
+        Empty.STRINGS);
+
+    addOrReplaceResource("test.Test",
+        "package test;",
+        "import jsinterop.annotations.JsMethod;",
+        "public class Test {",
+        "  @JsMethod",
+        "  public static void receivesJsoInterface(JsoIntf i) {};",
+        "}"
+    );
+    analyzeSnippet("Test.receivesJsoInterface(null);").assertOnlyInstantiatedTypes(
+        "JsoIntf", "SingleJso", "JavaScriptObject", "Object");
+  }
+
+    /**
+     * Tests that the JavaScriptObject type gets rescued in the three specific
+     * circumstances where values can pass from JS into Java.
+     */
+  public void testRescueJavaScriptObjectReturnedFromFieldReference() throws Exception {
+    addJsoResources();
+    addSnippetImport("test.Test");
+
+    addOrReplaceResource("test.Test",
+        "package test;",
+        "import jsinterop.annotations.JsType;",
+        "@JsType(isNative = true)",
+        "public class Test {",
+        "  public static JsoIntf field;",
+        "}"
+    );
+    analyzeSnippet("Test.field.hashCode();").assertOnlyInstantiatedTypes(
+        "JsoIntf", "SingleJso", "JavaScriptObject", "Object",
+        // These are all live because of the method Test.toString can be referenced externally.
+        "String", "Comparable", "CharSequence", "Serializable");
+
+    addOrReplaceResource("test.Test",
+        "package test;",
+        "import jsinterop.annotations.JsType;",
+        "@JsType(isNative = true)",
+        "public class Test {",
+        "  public static SingleJso field;",
+        "}"
+    );
+    analyzeSnippet("Test.field.hashCode();").assertOnlyInstantiatedTypes(
+        "JsoIntf", "SingleJso", "JavaScriptObject", "Object",
+        // These are all live because of the method Test.toString can be referenced externally.
+        "String", "Comparable", "CharSequence", "Serializable");
+  }
+
+  private void addOrReplaceResource(String qualifiedTypeName, final String... source) {
+    sourceOracle.addOrReplace(
+        new MockJavaResource(qualifiedTypeName) {
+          @Override
+          public CharSequence getContent() {
+            return Joiner.on("\n").join(source);
+          }
+        });
+    }
+
+  private void addJsoResources() {
+    addOrReplaceResource("test.JsoIntf",
+        "package test;",
+        "import com.google.gwt.core.client.JavaScriptObject;",
+        "public interface JsoIntf {",
+        "  public int getAny();",
+        "}");
+    addOrReplaceResource("test.UpRefIntf",
+        "package test;",
+        "import com.google.gwt.core.client.JavaScriptObject;",
+        "public interface UpRefIntf {",
+        "  public int getFoo();",
+        "}");
+    addOrReplaceResource("test.NonImplementor",
+        "package test;",
+        "import com.google.gwt.core.client.JavaScriptObject;",
+        "public class NonImplementor extends JavaScriptObject {",
+        "  protected NonImplementor() {}",
+        "  final public native int getFoo() /*-{ return 0; }-*/;",
+        "}");
+    addOrReplaceResource("test.SingleJso",
+        "package test;",
+        "import com.google.gwt.core.client.JavaScriptObject;",
+        "final public class SingleJso extends JavaScriptObject implements JsoIntf {",
+        "  protected SingleJso() {}",
+        "  public native int getAny() /*-{ return 1; }-*/;",
+        "}");
+  }
+
   private Result analyzeSnippet(String codeSnippet)
       throws UnableToCompleteException {
     JProgram program = compileSnippet("void", codeSnippet, true);
@@ -266,4 +327,5 @@
     cfa.traverseFrom(findMainMethod(program));
     return new Result(program, cfa);
   }
+
 }