diff --git a/idea/idea-core/src/org/jetbrains/kotlin/idea/core/script/configuration/utils/ScriptClassRootsUpdater.kt b/idea/idea-core/src/org/jetbrains/kotlin/idea/core/script/configuration/utils/ScriptClassRootsUpdater.kt
index 4e55bfcbbd2..64a3d5b6b2d 100644
--- a/idea/idea-core/src/org/jetbrains/kotlin/idea/core/script/configuration/utils/ScriptClassRootsUpdater.kt
+++ b/idea/idea-core/src/org/jetbrains/kotlin/idea/core/script/configuration/utils/ScriptClassRootsUpdater.kt
@@ -94,7 +94,7 @@ class ScriptClassRootsUpdater(
         if (!invalidated) return
         invalidated = false
 
-        if (syncUpdateRequired) {
+        if (syncUpdateRequired || ApplicationManager.getApplication().isUnitTestMode) {
             syncUpdateRequired = false
             updateSynchronously()
         } else {