diff --git a/java/java-analysis-impl/src/com/intellij/codeInspection/bytecodeAnalysis/ProjectBytecodeAnalysis.java b/java/java-analysis-impl/src/com/intellij/codeInspection/bytecodeAnalysis/ProjectBytecodeAnalysis.java
index 1258db655d49..374f2072d571 100644
--- a/java/java-analysis-impl/src/com/intellij/codeInspection/bytecodeAnalysis/ProjectBytecodeAnalysis.java
+++ b/java/java-analysis-impl/src/com/intellij/codeInspection/bytecodeAnalysis/ProjectBytecodeAnalysis.java
@@ -30,6 +30,7 @@ import com.intellij.psi.search.ProjectScope;
 import com.intellij.psi.util.CachedValueProvider;
 import com.intellij.psi.util.CachedValuesManager;
 import com.intellij.psi.util.PsiFormatUtil;
+import com.intellij.testFramework.LightVirtualFile;
 import com.intellij.util.IncorrectOperationException;
 import com.intellij.util.containers.Stack;
 import com.intellij.util.indexing.FileBasedIndex;
@@ -385,6 +386,7 @@ public class ProjectBytecodeAnalysis {
   private PsiAnnotation createAnnotationFromText(@NotNull final String text) throws IncorrectOperationException {
     PsiAnnotation annotation = JavaPsiFacade.getElementFactory(myProject).createAnnotationFromText(text, null);
     annotation.putUserData(INFERRED_ANNOTATION, Boolean.TRUE);
+    ((LightVirtualFile)annotation.getContainingFile().getViewProvider().getVirtualFile()).markReadOnly();
     return annotation;
   }
 }
diff --git a/java/java-psi-impl/src/com/intellij/codeInsight/BaseExternalAnnotationsManager.java b/java/java-psi-impl/src/com/intellij/codeInsight/BaseExternalAnnotationsManager.java
index 7e0d61d1948f..0f1e76a79c20 100644
--- a/java/java-psi-impl/src/com/intellij/codeInsight/BaseExternalAnnotationsManager.java
+++ b/java/java-psi-impl/src/com/intellij/codeInsight/BaseExternalAnnotationsManager.java
@@ -28,6 +28,7 @@ import com.intellij.pom.java.LanguageLevel;
 import com.intellij.psi.*;
 import com.intellij.psi.impl.source.*;
 import com.intellij.psi.util.PsiFormatUtil;
+import com.intellij.testFramework.LightVirtualFile;
 import com.intellij.util.Function;
 import com.intellij.util.IncorrectOperationException;
 import com.intellij.util.SmartList;
@@ -399,6 +400,7 @@ public abstract class BaseExternalAnnotationsManager extends ExternalAnnotations
 
   private static PsiAnnotation markAsExternalAnnotation(@NotNull PsiAnnotation annotation) {
     annotation.putUserData(EXTERNAL_ANNO_MARKER, Boolean.TRUE);
+    ((LightVirtualFile)annotation.getContainingFile().getViewProvider().getVirtualFile()).markReadOnly();
     return annotation;
   }
 
diff --git a/platform/core-api/src/com/intellij/testFramework/LightVirtualFile.java b/platform/core-api/src/com/intellij/testFramework/LightVirtualFile.java
index 719c23b46865..d80c41a325a2 100644
--- a/platform/core-api/src/com/intellij/testFramework/LightVirtualFile.java
+++ b/platform/core-api/src/com/intellij/testFramework/LightVirtualFile.java
@@ -34,6 +34,7 @@ import java.nio.charset.Charset;
 public class LightVirtualFile extends LightVirtualFileBase {
   private CharSequence myContent = "";
   private Language myLanguage;
+  private boolean myReadOnly;
 
   public LightVirtualFile() {
     this("");
@@ -127,6 +128,7 @@ public class LightVirtualFile extends LightVirtualFileBase {
   }
 
   private void setContent(@NotNull CharSequence content) {
+    assert !myReadOnly;
     //StringUtil.assertValidSeparators(content);
     myContent = content;
   }
@@ -136,6 +138,11 @@ public class LightVirtualFile extends LightVirtualFileBase {
     return myContent;
   }
 
+  public void markReadOnly() {
+    setWritable(false);
+    myReadOnly = true;
+  }
+
   @Override
   public String toString() {
     return "LightVirtualFile: " + getPresentableUrl();