diff --git a/plugins/kotlin/j2k/services/src/org/jetbrains/kotlin/nj2k/postProcessing/processings/MergePropertyWithConstructorParameterProcessing.kt b/plugins/kotlin/j2k/services/src/org/jetbrains/kotlin/nj2k/postProcessing/processings/MergePropertyWithConstructorParameterProcessing.kt
index 9f205ac8786c..6fe34a138c9d 100644
--- a/plugins/kotlin/j2k/services/src/org/jetbrains/kotlin/nj2k/postProcessing/processings/MergePropertyWithConstructorParameterProcessing.kt
+++ b/plugins/kotlin/j2k/services/src/org/jetbrains/kotlin/nj2k/postProcessing/processings/MergePropertyWithConstructorParameterProcessing.kt
@@ -78,7 +78,7 @@ class MergePropertyWithConstructorParameterProcessing : ElementsBasedPostProcess
     }
 
     override fun runProcessing(elements: List<PsiElement>, converterContext: NewJ2kConverterContext) {
-        for (klass in elements.descendantsOfType<KtClass>()) {
+        for (klass in runReadAction { elements.descendantsOfType<KtClass>() }) {
             convertClass(klass)
         }
     }