diff --git a/runtime/com/redhat/ceylon/compiler/java/runtime/model/RuntimeModelLoader.java b/runtime/com/redhat/ceylon/compiler/java/runtime/model/RuntimeModelLoader.java
index 4ffefff5d..5e100471c 100644
--- a/runtime/com/redhat/ceylon/compiler/java/runtime/model/RuntimeModelLoader.java
+++ b/runtime/com/redhat/ceylon/compiler/java/runtime/model/RuntimeModelLoader.java
@@ -5,10 +5,15 @@
 import java.util.List;
 import java.util.Map;
 
+import org.jboss.modules.ModuleClassLoader;
+
 import com.redhat.ceylon.cmr.api.ArtifactResult;
 import com.redhat.ceylon.cmr.impl.JULLogger;
 import com.redhat.ceylon.compiler.loader.impl.reflect.CachedTOCJars;
 import com.redhat.ceylon.compiler.loader.impl.reflect.ReflectionModelLoader;
+import com.redhat.ceylon.compiler.loader.impl.reflect.mirror.ReflectionClass;
+import com.redhat.ceylon.compiler.loader.impl.reflect.mirror.ReflectionUtils;
+import com.redhat.ceylon.compiler.loader.mirror.ClassMirror;
 import com.redhat.ceylon.compiler.loader.model.LazyModule;
 import com.redhat.ceylon.compiler.typechecker.analyzer.ModuleManager;
 import com.redhat.ceylon.compiler.typechecker.model.Module;
@@ -17,6 +22,7 @@
 public class RuntimeModelLoader extends ReflectionModelLoader {
 
     private Map<Module,ClassLoader> classLoaders = new HashMap<Module,ClassLoader>();
+    private Map<String, Module> moduleCache = new HashMap<String, Module>();
     private CachedTOCJars jars = new CachedTOCJars();
 
     public RuntimeModelLoader(ModuleManager moduleManager, Modules modules) {
@@ -24,35 +30,31 @@ public RuntimeModelLoader(ModuleManager moduleManager, Modules modules) {
     }
 
     @Override
-    protected List<String> getPackageList(String packageName) {
+    protected List<String> getPackageList(Module module, String packageName) {
         return jars.getPackageList(packageName);
     }
 
     @Override
-    protected boolean packageExists(String packageName) {
+    protected boolean packageExists(Module module, String packageName) {
         return jars.packageExists(packageName);
     }
 
     @Override
-    protected Class<?> loadClass(String name) {
-        for(ClassLoader cl : classLoaders.values()){
-            try{
-                return cl.loadClass(name);
-            }catch(ClassNotFoundException x){
-                // keep trying
-            }
+    protected Class<?> loadClass(Module module, String name) {
+        ClassLoader classLoader = classLoaders.get(module);
+        if(classLoader == null)
+            return null;
+        try{
+            return classLoader.loadClass(name);
+        }catch(ClassNotFoundException x){
+            return null;
         }
-        return null;
-//        // try the system class loader
-//        try {
-//            return ClassLoader.getSystemClassLoader().loadClass(name);
-//        } catch (ClassNotFoundException e) {
-//            return null;
-//        }
     }
 
     @Override
     public void addModuleToClassPath(Module module, ArtifactResult artifact) {
+        String cacheKey = cacheKeyByModule(module.getNameAsString(), module.getVersion());
+        moduleCache.put(cacheKey, module);
         if(artifact == null)
             return;
         File file = artifact.artifact();
@@ -66,4 +68,33 @@ public void addModuleClassLoader(Module module, ClassLoader classLoader) {
         classLoaders.put(module, classLoader);
     }
 
+    @Override
+    protected Module findModuleForClassMirror(ClassMirror classMirror) {
+        Class<?> klass = ((ReflectionClass)classMirror).klass;
+        return findModuleForClass(klass);
+    }
+
+    public Module findModuleForClass(Class<?> klass){
+        ClassLoader cl = klass.getClassLoader();
+        if(cl instanceof ModuleClassLoader){
+            ModuleClassLoader classLoader = (ModuleClassLoader)cl;
+            org.jboss.modules.Module jbossModule = classLoader.getModule();
+            String name = jbossModule.getIdentifier().getName();
+            String version = jbossModule.getIdentifier().getSlot();
+            String cacheKey = cacheKeyByModule(name, version);
+            return moduleCache.get(cacheKey);
+        }else{
+            // revert to a single classloader version?
+            // FIXME: perhaps we can have other one-classloader-to-one-module setups than jboss modules?
+            String pkgName = ReflectionUtils.getPackageName(klass);
+            return lookupModuleInternal(pkgName);
+        }
+    }
+    
+    private String cacheKeyByModule(String name, String version) {
+        if(name.equals(Module.DEFAULT_MODULE_NAME))
+            return name + "/"; // no version
+        return name + "/" + version;
+    }
+
 }
diff --git a/runtime/com/redhat/ceylon/compiler/java/runtime/model/RuntimeModuleManager.java b/runtime/com/redhat/ceylon/compiler/java/runtime/model/RuntimeModuleManager.java
index 1ee0fe93e..018146d64 100644
--- a/runtime/com/redhat/ceylon/compiler/java/runtime/model/RuntimeModuleManager.java
+++ b/runtime/com/redhat/ceylon/compiler/java/runtime/model/RuntimeModuleManager.java
@@ -61,10 +61,10 @@ public void loadModule(String name, String version, ArtifactResult artifact, Cla
         modelLoader.addModuleToClassPath(module, artifact);
         modelLoader.addModuleClassLoader(module, classLoader);
         module.setAvailable(true);
+        
         if(!module.isDefault()){
-            Module compiledModule = modelLoader.loadCompiledModule(name);
             // FIXME: dependencies of Ceylon modules?
-            if(compiledModule == null){
+            if(!modelLoader.loadCompiledModule(module)){
                 // we didn't find module.class so it must be a java module if it's not the default module
                 ((LazyModule)module).setJava(true);
 
@@ -86,4 +86,8 @@ public void loadModule(String name, String version, ArtifactResult artifact, Cla
     public RuntimeModelLoader getModelLoader() {
         return (RuntimeModelLoader) super.getModelLoader();
     }
+    
+    public Module findModuleForClass(java.lang.Class<?> klass){
+        return getModelLoader().findModuleForClass(klass);
+    }
 }
diff --git a/runtime/com/redhat/ceylon/compiler/java/runtime/model/TypeDescriptor.java b/runtime/com/redhat/ceylon/compiler/java/runtime/model/TypeDescriptor.java
index 468d39719..a4f9309be 100644
--- a/runtime/com/redhat/ceylon/compiler/java/runtime/model/TypeDescriptor.java
+++ b/runtime/com/redhat/ceylon/compiler/java/runtime/model/TypeDescriptor.java
@@ -5,6 +5,7 @@
 
 import com.redhat.ceylon.compiler.loader.ModelLoader.DeclarationType;
 import com.redhat.ceylon.compiler.typechecker.model.IntersectionType;
+import com.redhat.ceylon.compiler.typechecker.model.Module;
 import com.redhat.ceylon.compiler.typechecker.model.NothingType;
 import com.redhat.ceylon.compiler.typechecker.model.ProducedType;
 import com.redhat.ceylon.compiler.typechecker.model.TypeDeclaration;
@@ -79,7 +80,8 @@ public ProducedType toProducedType(RuntimeModuleManager moduleManager){
         
         public ProducedType toProducedType(ProducedType qualifyingType, RuntimeModuleManager moduleManager){
             String typeName = klass.getName();
-            TypeDeclaration decl = (TypeDeclaration) moduleManager.getModelLoader().getDeclaration(typeName, DeclarationType.TYPE);
+            Module module = moduleManager.findModuleForClass(klass);
+            TypeDeclaration decl = (TypeDeclaration) moduleManager.getModelLoader().getDeclaration(module, typeName, DeclarationType.TYPE);
             List<ProducedType> typeArgs = new ArrayList<ProducedType>(typeArguments.length);
             for(TypeDescriptor typeArg : typeArguments){
                 typeArgs.add(typeArg.toProducedType(moduleManager));