diff --git a/idea/src/org/jetbrains/kotlin/idea/versions/OutdatedKotlinRuntimeChecker.kt b/idea/src/org/jetbrains/kotlin/idea/versions/OutdatedKotlinRuntimeChecker.kt
index c407cb2bfbd..8ebf529b0e0 100644
--- a/idea/src/org/jetbrains/kotlin/idea/versions/OutdatedKotlinRuntimeChecker.kt
+++ b/idea/src/org/jetbrains/kotlin/idea/versions/OutdatedKotlinRuntimeChecker.kt
@@ -85,7 +85,7 @@ fun notifyOutdatedKotlinRuntime(project: Project, outdatedLibraries: Collection<
         "<p><a href=\"update\">Update Runtime</a> <a href=\"ignore\">Ignore</a></p>"
     }
     else {
-        val libraryNames = outdatedLibraries.joinToString { it.library.name!! }
+        val libraryNames = outdatedLibraries.joinToString { it.library.name ?: "unknown library" }
 
         "<p>Version of Kotlin runtime is outdated in several libraries ($libraryNames). Plugin version is $pluginVersion.</p>" +
         "<p>Runtime libraries should be updated to avoid compatibility problems.</p>" +