diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/resolve/lazy/EmptyPackageMemberDeclarationProvider.java b/compiler/frontend/src/org/jetbrains/jet/lang/resolve/lazy/EmptyPackageMemberDeclarationProvider.java
new file mode 100644
index 00000000000..c2363278804
--- /dev/null
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/resolve/lazy/EmptyPackageMemberDeclarationProvider.java
@@ -0,0 +1,71 @@
+/*
+ * Copyright 2010-2012 JetBrains s.r.o.
+ *
+ * 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.
+ */
+
+package org.jetbrains.jet.lang.resolve.lazy;
+
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.jet.lang.psi.JetClassOrObject;
+import org.jetbrains.jet.lang.psi.JetDeclaration;
+import org.jetbrains.jet.lang.psi.JetNamedFunction;
+import org.jetbrains.jet.lang.psi.JetProperty;
+import org.jetbrains.jet.lang.resolve.name.FqName;
+import org.jetbrains.jet.lang.resolve.name.Name;
+
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * @author abreslav
+ */
+public class EmptyPackageMemberDeclarationProvider implements PackageMemberDeclarationProvider {
+
+    public static final EmptyPackageMemberDeclarationProvider INSTANCE = new EmptyPackageMemberDeclarationProvider();
+
+    private EmptyPackageMemberDeclarationProvider() {}
+
+    @Override
+    public boolean isPackageDeclared(@NotNull Name name) {
+        return false;
+    }
+
+    @Override
+    public Collection<FqName> getAllDeclaredPackages() {
+        return Collections.emptyList();
+    }
+
+    @Override
+    public List<JetDeclaration> getAllDeclarations() {
+        return Collections.emptyList();
+    }
+
+    @NotNull
+    @Override
+    public Collection<JetNamedFunction> getFunctionDeclarations(@NotNull Name name) {
+        return Collections.emptyList();
+    }
+
+    @NotNull
+    @Override
+    public Collection<JetProperty> getPropertyDeclarations(@NotNull Name name) {
+        return Collections.emptyList();
+    }
+
+    @Override
+    public JetClassOrObject getClassOrObjectDeclaration(@NotNull Name name) {
+        return null;
+    }
+}
diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/resolve/lazy/ExternalNamespaceProvider.java b/compiler/frontend/src/org/jetbrains/jet/lang/resolve/lazy/ExternalNamespaceProvider.java
new file mode 100644
index 00000000000..979a6ee11c7
--- /dev/null
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/resolve/lazy/ExternalNamespaceProvider.java
@@ -0,0 +1,7 @@
+package org.jetbrains.jet.lang.resolve.lazy;
+
+/**
+ * @author abreslav
+ */
+public class ExternalNamespaceProvider {
+}
diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/resolve/lazy/FileBasedDeclarationProviderFactory.java b/compiler/frontend/src/org/jetbrains/jet/lang/resolve/lazy/FileBasedDeclarationProviderFactory.java
index 8142eef9b65..8f91ccae017 100644
--- a/compiler/frontend/src/org/jetbrains/jet/lang/resolve/lazy/FileBasedDeclarationProviderFactory.java
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/resolve/lazy/FileBasedDeclarationProviderFactory.java
@@ -17,6 +17,7 @@
 package org.jetbrains.jet.lang.resolve.lazy;
 
 import com.google.common.base.Predicate;
+import com.google.common.base.Predicates;
 import com.google.common.collect.*;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.jet.lang.psi.JetFile;
@@ -40,10 +41,17 @@ public class FileBasedDeclarationProviderFactory implements DeclarationProviderF
     private final Map<FqName, PackageMemberDeclarationProvider> packageDeclarationProviders = Maps.newHashMap();
     //private final Map<JetClassOrObject, ClassMemberDeclarationProvider> classMemberDeclarationProviders = Maps.newHashMap();
 
+    private final Predicate<FqName> isPackageDeclaredExternally;
+
     private boolean indexed = false;
 
     public FileBasedDeclarationProviderFactory(@NotNull Collection<JetFile> files) {
+        this(files, Predicates.<FqName>alwaysFalse());
+    }
+
+    public FileBasedDeclarationProviderFactory(@NotNull Collection<JetFile> files, Predicate<FqName> isPackageDeclaredExternally) {
         this.allFiles = files;
+        this.isPackageDeclaredExternally = isPackageDeclaredExternally;
     }
 
     private void createIndex() {
@@ -69,11 +77,15 @@ public class FileBasedDeclarationProviderFactory implements DeclarationProviderF
         }
     }
 
-    /*package*/ boolean isPackageDeclared(@NotNull FqName packageFqName) {
+    /*package*/ boolean isPackageDeclaredExplicitly(@NotNull FqName packageFqName) {
         createIndex();
         return declaredPackages.contains(packageFqName);
     }
 
+    /*package*/ boolean isPackageDeclared(@NotNull FqName packageFqName) {
+        return isPackageDeclaredExplicitly(packageFqName) || isPackageDeclaredExternally.apply(packageFqName);
+    }
+
     /*package*/ Collection<FqName> getAllDeclaredSubPackagesOf(@NotNull final FqName parent) {
         return Collections2.filter(declaredPackages, new Predicate<FqName>() {
             @Override
@@ -92,7 +104,12 @@ public class FileBasedDeclarationProviderFactory implements DeclarationProviderF
             return declarationProvider;
         }
 
-        if (!isPackageDeclared(packageFqName)) return null;
+        if (!isPackageDeclaredExplicitly(packageFqName)) {
+            if (isPackageDeclaredExternally.apply(packageFqName)) {
+                return EmptyPackageMemberDeclarationProvider.INSTANCE;
+            }
+            return null;
+        }
 
         FileBasedPackageMemberDeclarationProvider provider =
                 new FileBasedPackageMemberDeclarationProvider(packageFqName, this, filesByPackage.get(packageFqName));