diff --git a/compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/structure/impl/JavaPackageImpl.kt b/compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/structure/impl/JavaPackageImpl.kt
index be51bd32c90..9748cf0454c 100644
--- a/compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/structure/impl/JavaPackageImpl.kt
+++ b/compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/structure/impl/JavaPackageImpl.kt
@@ -28,7 +28,7 @@ import com.intellij.psi.search.GlobalSearchScope
 
 public class JavaPackageImpl(psiPackage: PsiPackage, private val scope: GlobalSearchScope) : JavaElementImpl<PsiPackage>(psiPackage), JavaPackage {
 
-    override fun getClasses(nameFilter: (Name) -> Boolean): MutableCollection<JavaClass> {
+    override fun getClasses(nameFilter: (Name) -> Boolean): Collection<JavaClass> {
         val psiClasses = getPsi().getClasses(scope).filter {
             val name = it.getName()
             name != null && nameFilter(Name.identifier(name))
diff --git a/core/descriptor.loader.java/src/org/jetbrains/jet/lang/resolve/java/lazy/descriptors/LazyJavaMemberScope.kt b/core/descriptor.loader.java/src/org/jetbrains/jet/lang/resolve/java/lazy/descriptors/LazyJavaMemberScope.kt
index 13dfc84866f..b6585ab7057 100644
--- a/core/descriptor.loader.java/src/org/jetbrains/jet/lang/resolve/java/lazy/descriptors/LazyJavaMemberScope.kt
+++ b/core/descriptor.loader.java/src/org/jetbrains/jet/lang/resolve/java/lazy/descriptors/LazyJavaMemberScope.kt
@@ -49,6 +49,8 @@ public abstract class LazyJavaMemberScope(
         protected val c: LazyJavaResolverContextWithTypes,
         private val containingDeclaration: DeclarationDescriptor
 ) : JetScope {
+    // this lazy value is not used at all in LazyPackageFragmentScopeForJavaPackage because we do not use caching there
+    // but is placed in the base class to not duplicate code
     private val allDescriptors = c.storageManager.createRecursionTolerantLazyValue<Collection<DeclarationDescriptor>>(
             { computeDescriptors(JetScope.ALL_KINDS_MASK, JetScope.ALL_NAME_FILTER) },
             // This is to avoid the following recursive case:
@@ -280,6 +282,8 @@ public abstract class LazyJavaMemberScope(
     }
 
     override fun getProperties(name: Name): Collection<VariableDescriptor> = properties(name)
+
+    // we do not have nameFilter here because it only makes sense in package but java package does not contain any properties
     protected open fun getAllPropertyNames(): Collection<Name> = memberIndex().getAllFieldNames()
 
     override fun getLocalVariable(name: Name): VariableDescriptor? = null
diff --git a/idea/idea-analysis/src/org/jetbrains/jet/plugin/stubindex/resolve/StubBasedPackageMemberDeclarationProvider.kt b/idea/idea-analysis/src/org/jetbrains/jet/plugin/stubindex/resolve/StubBasedPackageMemberDeclarationProvider.kt
index 2581173436e..24b4e3f9399 100644
--- a/idea/idea-analysis/src/org/jetbrains/jet/plugin/stubindex/resolve/StubBasedPackageMemberDeclarationProvider.kt
+++ b/idea/idea-analysis/src/org/jetbrains/jet/plugin/stubindex/resolve/StubBasedPackageMemberDeclarationProvider.kt
@@ -63,7 +63,8 @@ public class StubBasedPackageMemberDeclarationProvider(
                 .stream()
                 .map { FqName(it) }
                 .filter { !it.isRoot() && it.parent() == fqName && nameFilter(it.shortName()) }
-                .flatMapTo(this) { index[it.asString(), project, searchScope].stream() }
+                .toSet()
+                .flatMapTo(this) { index[it.asString(), project, searchScope] }
     }
 
     override fun getClassOrObjectDeclarations(name: Name): Collection<JetClassLikeInfo> {