diff --git a/compiler/backend/src/org/jetbrains/kotlin/codegen/JvmCodegenUtil.java b/compiler/backend/src/org/jetbrains/kotlin/codegen/JvmCodegenUtil.java
index 5f2486bd0c0..67bfbd9796a 100644
--- a/compiler/backend/src/org/jetbrains/kotlin/codegen/JvmCodegenUtil.java
+++ b/compiler/backend/src/org/jetbrains/kotlin/codegen/JvmCodegenUtil.java
@@ -33,6 +33,7 @@ import org.jetbrains.kotlin.descriptors.*;
 import org.jetbrains.kotlin.load.java.descriptors.JavaClassDescriptor;
 import org.jetbrains.kotlin.load.java.lazy.descriptors.LazyJavaPackageFragment;
 import org.jetbrains.kotlin.load.kotlin.KotlinJvmBinaryClass;
+import org.jetbrains.kotlin.load.kotlin.ModuleMapping;
 import org.jetbrains.kotlin.load.kotlin.VirtualFileKotlinClass;
 import org.jetbrains.kotlin.load.kotlin.incremental.IncrementalPackageFragmentProvider;
 import org.jetbrains.kotlin.psi.JetFile;
@@ -253,6 +254,6 @@ public class JvmCodegenUtil {
 
     @NotNull
     public static String getMappingFileName(@NotNull String moduleName) {
-        return "META-INF/" + moduleName + ".kotlin_module";
+        return "META-INF/" + moduleName + "." + ModuleMapping.MAPPING_FILE_EXT;
     }
 }
diff --git a/compiler/frontend/src/org/jetbrains/kotlin/idea/KotlinModuleFileType.java b/compiler/frontend/src/org/jetbrains/kotlin/idea/KotlinModuleFileType.java
index b6254e17d0b..e2e4cf874f4 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/idea/KotlinModuleFileType.java
+++ b/compiler/frontend/src/org/jetbrains/kotlin/idea/KotlinModuleFileType.java
@@ -49,7 +49,7 @@ public class KotlinModuleFileType implements FileType {
     @Override
     @NotNull
     public String getDescription() {
-        return getName();
+        return "Kotlin module info: contains package part mappings";
     }
 
     @Override
diff --git a/core/descriptors.runtime/src/org/jetbrains/kotlin/load/kotlin/reflect/RuntimePackagePartProvider.kt b/core/descriptors.runtime/src/org/jetbrains/kotlin/load/kotlin/reflect/RuntimePackagePartProvider.kt
index 5b903542741..f444b74c15d 100644
--- a/core/descriptors.runtime/src/org/jetbrains/kotlin/load/kotlin/reflect/RuntimePackagePartProvider.kt
+++ b/core/descriptors.runtime/src/org/jetbrains/kotlin/load/kotlin/reflect/RuntimePackagePartProvider.kt
@@ -29,7 +29,7 @@ class RuntimePackagePartProvider(val classLoader : ClassLoader) : PackagePartPro
         if (moduleName == null) return
 
         module2Mapping.putIfAbsent(moduleName, lazy {
-            val resourceAsStream: InputStream = classLoader.getResourceAsStream("META-INF/$moduleName.kotlin_module") ?: return@lazy ModuleMapping()
+           val resourceAsStream: InputStream = classLoader.getResourceAsStream("META-INF/$moduleName.${ModuleMapping.MAPPING_FILE_EXT}") ?: return@lazy ModuleMapping()
 
             try {
                 return@lazy ModuleMapping(resourceAsStream.readBytes())
diff --git a/idea/src/org/jetbrains/kotlin/idea/KotlinModuleFileFactory.java b/idea/src/org/jetbrains/kotlin/idea/KotlinModuleFileFactory.java
index f0eac11a4dd..84ab3a7fb37 100644
--- a/idea/src/org/jetbrains/kotlin/idea/KotlinModuleFileFactory.java
+++ b/idea/src/org/jetbrains/kotlin/idea/KotlinModuleFileFactory.java
@@ -24,6 +24,6 @@ import org.jetbrains.annotations.NotNull;
 public class KotlinModuleFileFactory extends FileTypeFactory {
     @Override
     public void createFileTypes(@NotNull FileTypeConsumer consumer) {
-        consumer.consume(KotlinModuleFileType.INSTANCE, "kotlin_module");
+        consumer.consume(KotlinModuleFileType.INSTANCE, KotlinModuleFileType.EXTENSION);
     }
 }