diff --git a/idea/idea-jvm/src/org/jetbrains/kotlin/idea/debugger/evaluate/KotlinDebuggerCaches.kt b/idea/idea-jvm/src/org/jetbrains/kotlin/idea/debugger/evaluate/KotlinDebuggerCaches.kt
index e6a45f49540..aec0423fc2f 100644
--- a/idea/idea-jvm/src/org/jetbrains/kotlin/idea/debugger/evaluate/KotlinDebuggerCaches.kt
+++ b/idea/idea-jvm/src/org/jetbrains/kotlin/idea/debugger/evaluate/KotlinDebuggerCaches.kt
@@ -144,7 +144,7 @@ class KotlinDebuggerCaches(project: Project) {
             val cache = getInstance(runReadAction { psiElement.project })
 
             val file = runReadAction { psiElement.containingFile as KtFile }
-            val isInLibrary = LibraryUtil.findLibraryEntry(file.virtualFile, file.project) != null
+            val isInLibrary = runReadAction { LibraryUtil.findLibraryEntry(file.virtualFile, file.project) } != null
 
             val key = if (!isInLibrary) file else psiElement