diff --git a/idea/src/org/jetbrains/jet/plugin/libraries/JetClsNavigationPolicy.java b/idea/src/org/jetbrains/jet/plugin/libraries/JetClsNavigationPolicy.java
index 3a3ca4e3e3d..0a824090c0a 100644
--- a/idea/src/org/jetbrains/jet/plugin/libraries/JetClsNavigationPolicy.java
+++ b/idea/src/org/jetbrains/jet/plugin/libraries/JetClsNavigationPolicy.java
@@ -22,7 +22,6 @@ import com.intellij.psi.impl.compiled.*;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.jetbrains.jet.lang.psi.JetDeclaration;
-import org.jetbrains.jet.plugin.libraries.JetDecompiledData;
 
 /**
  * @author Evgeny Gerashchenko
@@ -50,7 +49,7 @@ public class JetClsNavigationPolicy implements ClsCustomNavigationPolicy {
     @Nullable
     private static JetDeclaration getJetDeclarationByClsElement(ClsElementImpl clsElement) {
         VirtualFile virtualFile = clsElement.getContainingFile().getVirtualFile();
-        if (virtualFile == null || JetDecompiledData.getClsFileIfKotlin(clsElement.getProject(), virtualFile) == null) {
+        if (virtualFile == null || !JetDecompiledData.isKotlinFile(clsElement.getProject(), virtualFile)) {
             return null;
         }
         JetDecompiledData decompiledData = JetDecompiledData.getDecompiledData((ClsFileImpl) clsElement.getContainingFile());
diff --git a/idea/src/org/jetbrains/jet/plugin/libraries/JetContentBasedFileSubstitutor.java b/idea/src/org/jetbrains/jet/plugin/libraries/JetContentBasedFileSubstitutor.java
index d4c47795b9a..a6c6cff9829 100644
--- a/idea/src/org/jetbrains/jet/plugin/libraries/JetContentBasedFileSubstitutor.java
+++ b/idea/src/org/jetbrains/jet/plugin/libraries/JetContentBasedFileSubstitutor.java
@@ -34,14 +34,15 @@ public class JetContentBasedFileSubstitutor implements ContentBasedClassFileProc
 
     @Override
     public boolean isApplicable(Project project, VirtualFile file) {
-        return JetDecompiledData.getClsFileIfKotlin(project, file) != null;
+        return JetDecompiledData.isKotlinFile(project, file);
     }
 
     @NotNull
     @Override
     public String obtainFileText(Project project, VirtualFile file) {
-        ClsFileImpl clsFile = JetDecompiledData.getClsFileIfKotlin(project, file);
-        if (clsFile != null) {
+        if (JetDecompiledData.isKotlinFile(project, file)) {
+            ClsFileImpl clsFile = JetDecompiledData.getClsFile(project, file);
+            assert clsFile != null;
             return JetDecompiledData.getDecompiledData(clsFile).getJetFile().getText();
         }
         return "";
diff --git a/idea/src/org/jetbrains/jet/plugin/libraries/JetDecompiledData.java b/idea/src/org/jetbrains/jet/plugin/libraries/JetDecompiledData.java
index fa0f6cb8762..056e95d215d 100644
--- a/idea/src/org/jetbrains/jet/plugin/libraries/JetDecompiledData.java
+++ b/idea/src/org/jetbrains/jet/plugin/libraries/JetDecompiledData.java
@@ -21,7 +21,9 @@ import com.intellij.openapi.fileTypes.FileTypeManager;
 import com.intellij.openapi.project.Project;
 import com.intellij.openapi.util.Key;
 import com.intellij.openapi.vfs.VirtualFile;
-import com.intellij.psi.*;
+import com.intellij.psi.PsiClass;
+import com.intellij.psi.PsiFile;
+import com.intellij.psi.PsiManager;
 import com.intellij.psi.impl.compiled.ClsElementImpl;
 import com.intellij.psi.impl.compiled.ClsFileImpl;
 import org.jetbrains.annotations.NotNull;
@@ -58,9 +60,8 @@ public class JetDecompiledData {
         return myClsElementsToJetElements.get(clsElement);
     }
 
-    @Deprecated
     @Nullable
-    public static ClsFileImpl getClsFileIfKotlin(@NotNull Project project, @NotNull VirtualFile vFile) {
+    public static ClsFileImpl getClsFile(@NotNull Project project, @NotNull VirtualFile vFile) {
         if (!FileTypeManager.getInstance().isFileOfType(vFile, JavaClassFileType.INSTANCE)) {
             return null;
         }
@@ -72,8 +73,16 @@ public class JetDecompiledData {
         if (clsFile.getClasses().length != 1) {
             return null;
         }
+        return clsFile;
+    }
+
+    public static boolean isKotlinFile(@NotNull Project project, @NotNull VirtualFile vFile) {
+        ClsFileImpl clsFile = getClsFile(project, vFile);
+        if (clsFile == null) {
+            return false;
+        }
         PsiClass psiClass = clsFile.getClasses()[0];
-        return DecompiledDataFactory.isKotlinNamespaceClass(psiClass) || DecompiledDataFactory.isKotlinClass(psiClass) ? clsFile : null;
+        return DecompiledDataFactory.isKotlinNamespaceClass(psiClass) || DecompiledDataFactory.isKotlinClass(psiClass);
     }
 
     @NotNull