diff --git a/idea/idea-analysis/src/org/jetbrains/kotlin/idea/project/Platform.kt b/idea/idea-analysis/src/org/jetbrains/kotlin/idea/project/Platform.kt
index ba548819682..bf1ef52c970 100644
--- a/idea/idea-analysis/src/org/jetbrains/kotlin/idea/project/Platform.kt
+++ b/idea/idea-analysis/src/org/jetbrains/kotlin/idea/project/Platform.kt
@@ -169,16 +169,27 @@ val Module.languageVersionSettings: LanguageVersionSettings
         return cachedValue.value
     }
 
-@TestOnly // public for tests
-fun Module.setLanguageVersionSettings(value: LanguageVersionSettings) =
-    putUserData(
-        LANGUAGE_VERSION_SETTINGS,
-        CachedValuesManager.getManager(project).createCachedValue({
-                                                                      CachedValueProvider.Result(
-                                                                          value, ProjectRootModificationTracker.getInstance(project)
-                                                                      )
-                                                                  }, false)
-    )
+@TestOnly
+fun Module.withLanguageVersionSettings(value: LanguageVersionSettings, body: () -> Unit) {
+    val previousLanguageVersionSettings = getUserData(LANGUAGE_VERSION_SETTINGS)
+    try {
+        putUserData(
+            LANGUAGE_VERSION_SETTINGS,
+            CachedValuesManager.getManager(project).createCachedValue(
+                {
+                    CachedValueProvider.Result(
+                        value, ProjectRootModificationTracker.getInstance(project)
+                    )
+                },
+                false
+            )
+        )
+
+        body()
+    } finally {
+        putUserData(LANGUAGE_VERSION_SETTINGS, previousLanguageVersionSettings)
+    }
+}
 
 private fun Module.createCachedValueForLanguageVersionSettings(): CachedValue<LanguageVersionSettings> {
     return CachedValuesManager.getManager(project).createCachedValue({
diff --git a/idea/tests/org/jetbrains/kotlin/idea/run/RunConfigurationTest.kt b/idea/tests/org/jetbrains/kotlin/idea/run/RunConfigurationTest.kt
index c72a6405eeb..b84905b25ed 100644
--- a/idea/tests/org/jetbrains/kotlin/idea/run/RunConfigurationTest.kt
+++ b/idea/tests/org/jetbrains/kotlin/idea/run/RunConfigurationTest.kt
@@ -18,10 +18,11 @@ import com.intellij.psi.PsiManager
 import com.intellij.refactoring.RefactoringFactory
 import com.intellij.testFramework.MapDataContext
 import org.jetbrains.kotlin.checkers.languageVersionSettingsFromText
+import org.jetbrains.kotlin.config.LanguageVersionSettings
 import org.jetbrains.kotlin.config.LanguageVersionSettingsImpl
 import org.jetbrains.kotlin.idea.MainFunctionDetector
 import org.jetbrains.kotlin.idea.caches.resolve.resolveToDescriptorIfAny
-import org.jetbrains.kotlin.idea.project.setLanguageVersionSettings
+import org.jetbrains.kotlin.idea.project.withLanguageVersionSettings
 import org.jetbrains.kotlin.idea.search.allScope
 import org.jetbrains.kotlin.idea.stubindex.KotlinFullClassNameIndex
 import org.jetbrains.kotlin.idea.stubindex.KotlinTopLevelFunctionFqnNameIndex
@@ -58,13 +59,16 @@ class RunConfigurationTest : AbstractRunConfigurationTest() {
             createModuleResult.srcDir?.children?.filter { it.extension == "kt" }?.forEach {
                 val psiFile = PsiManager.getInstance(createModuleResult.module.project).findFile(it)
                 if (psiFile is KtFile) {
-                    psiFile.acceptChildren(
-                        object : KtVisitorVoid() {
-                            override fun visitNamedFunction(function: KtNamedFunction) {
-                                functionVisitor(createModuleResult.module, function)
-                            }
-                        },
-                    )
+                    val languageVersionSettings = languageVersionSettingsFromText(listOf(psiFile.text))
+                    module.withLanguageVersionSettings(languageVersionSettings) {
+                        psiFile.acceptChildren(
+                            object : KtVisitorVoid() {
+                                override fun visitNamedFunction(function: KtNamedFunction) {
+                                    functionVisitor(languageVersionSettings, function)
+                                }
+                            },
+                        )
+                    }
                 }
             }
         }
@@ -209,7 +213,7 @@ class RunConfigurationTest : AbstractRunConfigurationTest() {
     }
 
     companion object {
-        private fun functionVisitor(module: Module, function: KtNamedFunction) {
+        private fun functionVisitor(fileLanguageSettings: LanguageVersionSettings, function: KtNamedFunction) {
             val project = function.project
             val file = function.containingKtFile
             val options = function.bodyExpression?.allChildren?.filterIsInstance<PsiComment>()
@@ -220,10 +224,7 @@ class RunConfigurationTest : AbstractRunConfigurationTest() {
                 val assertIsMain = "yes" in options
                 val assertIsNotMain = "no" in options
 
-                val languageVersionSettings = languageVersionSettingsFromText(listOf(file.text))
-                module.setLanguageVersionSettings(languageVersionSettings)
-                val isMainFunction =
-                    MainFunctionDetector(languageVersionSettings) { it.resolveToDescriptorIfAny() }.isMain(function)
+                val isMainFunction = MainFunctionDetector(fileLanguageSettings) { it.resolveToDescriptorIfAny() }.isMain(function)
 
                 if (assertIsMain) {
                     assertTrue("$file: The function ${function.fqName?.asString()} should be main", isMainFunction)