diff --git a/compiler/frontend/src/org/jetbrains/jet/analyzer/AnalyzerFacade.kt b/compiler/frontend/src/org/jetbrains/jet/analyzer/AnalyzerFacade.kt
index 337c900d28b..b42e7fc657a 100644
--- a/compiler/frontend/src/org/jetbrains/jet/analyzer/AnalyzerFacade.kt
+++ b/compiler/frontend/src/org/jetbrains/jet/analyzer/AnalyzerFacade.kt
@@ -38,15 +38,23 @@ public trait ResolverForModule {
 public trait ResolverForProject<M : ModuleInfo, R : ResolverForModule> {
     public fun resolverForModule(moduleInfo: M): R
     public fun descriptorForModule(moduleInfo: M): ModuleDescriptor
+    val allModules: Collection<M>
+}
+
+public class EmptyResolverForProject<M : ModuleInfo, R : ResolverForModule> : ResolverForProject<M, R> {
+    override fun resolverForModule(moduleInfo: M): R = throw IllegalStateException("Should not be called for $moduleInfo")
+    override fun descriptorForModule(moduleInfo: M) = throw IllegalStateException("Should not be called for $moduleInfo")
+    override val allModules: Collection<M> = listOf()
 }
 
 public class ResolverForProjectImpl<M : ModuleInfo, R : ResolverForModule>(
-        val descriptorByModule: Map<M, ModuleDescriptorImpl>
+        val descriptorByModule: Map<M, ModuleDescriptorImpl>,
+        val delegateResolver: ResolverForProject<M, R> = EmptyResolverForProject()
 ) : ResolverForProject<M, R> {
     val resolverByModuleDescriptor: MutableMap<ModuleDescriptor, R> = HashMap()
 
-    private val allModules: Collection<M> by Delegates.lazy {
-        descriptorByModule.keySet()
+    override val allModules: Collection<M> by Delegates.lazy {
+        (descriptorByModule.keySet() + delegateResolver.allModules).toSet()
     }
 
     private fun assertCorrectModuleInfo(moduleInfo: M) {
@@ -57,13 +65,13 @@ public class ResolverForProjectImpl<M : ModuleInfo, R : ResolverForModule>(
 
     override fun resolverForModule(moduleInfo: M): R {
         assertCorrectModuleInfo(moduleInfo)
-        val descriptor = descriptorByModule[moduleInfo]!!
+        val descriptor = descriptorByModule[moduleInfo] ?: return delegateResolver.resolverForModule(moduleInfo)
         return resolverByModuleDescriptor[descriptor]!!
     }
 
     override fun descriptorForModule(moduleInfo: M): ModuleDescriptorImpl {
         assertCorrectModuleInfo(moduleInfo)
-        return descriptorByModule[moduleInfo]!!
+        return descriptorByModule[moduleInfo] ?: return delegateResolver.descriptorForModule(moduleInfo) as ModuleDescriptorImpl
     }
 }
 
@@ -111,7 +119,8 @@ public trait AnalyzerFacade<out A : ResolverForModule, in P : PlatformAnalysisPa
             project: Project,
             modules: Collection<M>,
             modulesContent: (M) -> ModuleContent,
-            platformParameters: P
+            platformParameters: P,
+            delegateResolver: ResolverForProject<M, A> = EmptyResolverForProject()
     ): ResolverForProject<M, A> {
 
         fun createResolverForProject(): ResolverForProjectImpl<M, A> {
@@ -120,7 +129,7 @@ public trait AnalyzerFacade<out A : ResolverForModule, in P : PlatformAnalysisPa
                 module ->
                 descriptorByModule[module] = ModuleDescriptorImpl(module.name, defaultImports, platformToKotlinClassMap)
             }
-            return ResolverForProjectImpl(descriptorByModule)
+            return ResolverForProjectImpl(descriptorByModule, delegateResolver)
         }
 
         val resolverForProject = createResolverForProject()