diff --git a/java/java-tests/testSrc/com/intellij/java/propertyBased/JavaPsiIndexConsistencyTest.kt b/java/java-tests/testSrc/com/intellij/java/propertyBased/JavaPsiIndexConsistencyTest.kt
index f5a575a93ccf..d526792da478 100644
--- a/java/java-tests/testSrc/com/intellij/java/propertyBased/JavaPsiIndexConsistencyTest.kt
+++ b/java/java-tests/testSrc/com/intellij/java/propertyBased/JavaPsiIndexConsistencyTest.kt
@@ -35,6 +35,7 @@ import com.intellij.testFramework.propertyBased.PsiIndexConsistencyTester.Model
 import com.intellij.testFramework.propertyBased.PsiIndexConsistencyTester.RefKind
 import org.jetbrains.jetCheck.Generator
 import org.jetbrains.jetCheck.PropertyChecker
+import org.junit.Assert
 
 /**
  * @author peter
@@ -143,6 +144,14 @@ class JavaPsiIndexConsistencyTest : LightCodeInsightFixtureTestCase() {
 
   private object ClassRef : RefKind(){
     override fun loadRef(model: Model) = model.findPsiClass()
+    override fun checkDuplicates(oldValue: Any, newValue: Any) {
+      oldValue as PsiClass
+      newValue as PsiClass
+      if (oldValue.isValid && (newValue.containingFile as PsiJavaFile).classes.size == 1) {
+        // if there are >1 classes in the file, it could be that after reparse previously retrieved PsiClass instance is now pointing to a non-first one, and so there's no duplicate 
+        Assert.fail("Duplicate PSI elements: $oldValue and $newValue")
+      }
+    }
   }
 }
 
diff --git a/platform/testFramework/testSrc/com/intellij/testFramework/propertyBased/PsiIndexConsistencyTester.kt b/platform/testFramework/testSrc/com/intellij/testFramework/propertyBased/PsiIndexConsistencyTester.kt
index 8f71f980254d..307c2f3109c3 100644
--- a/platform/testFramework/testSrc/com/intellij/testFramework/propertyBased/PsiIndexConsistencyTester.kt
+++ b/platform/testFramework/testSrc/com/intellij/testFramework/propertyBased/PsiIndexConsistencyTester.kt
@@ -165,8 +165,8 @@ object PsiIndexConsistencyTester {
       override fun performAction(model: Model) {
         val oldValue = model.refs[kind]
         val newValue = kind.loadRef(model)
-        if (oldValue is PsiElement && oldValue.isValid && newValue is PsiElement && oldValue !== newValue) {
-          fail("Duplicate PSI elements: $oldValue and $newValue")
+        if (oldValue !== null && newValue !== null && oldValue !== newValue) {
+          kind.checkDuplicates(oldValue, newValue)
         }
         model.refs[kind] = newValue
       }
@@ -194,6 +194,12 @@ object PsiIndexConsistencyTester {
   abstract class RefKind {
 
     abstract fun loadRef(model: Model): Any?
+    
+    open fun checkDuplicates(oldValue: Any, newValue: Any) {
+      if (oldValue is PsiElement && oldValue.isValid && newValue is PsiElement) {
+        fail("Duplicate PSI elements: $oldValue and $newValue")
+      }
+    }
 
     object PsiFileRef : RefKind() {
       override fun loadRef(model: Model): Any? = model.findPsiFile()