JS IR: enable signature clash asserts in box tests
diff --git a/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/klib.kt b/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/klib.kt
index 2175ca6..09906c7 100644
--- a/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/klib.kt
+++ b/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/klib.kt
@@ -650,7 +650,7 @@
     val compatibilityMode = CompatibilityMode(abiVersion)
     val sourceBaseDirs = configuration[CommonConfigurationKeys.KLIB_RELATIVE_PATH_BASES] ?: emptyList()
     val absolutePathNormalization = configuration[CommonConfigurationKeys.KLIB_NORMALIZE_ABSOLUTE_PATH] ?: false
-    val signatureClashChecks = configuration[CommonConfigurationKeys.PRODUCE_KLIB_SIGNATURES_CLASH_CHECKS] ?: false
+    val signatureClashChecks = configuration[CommonConfigurationKeys.PRODUCE_KLIB_SIGNATURES_CLASH_CHECKS] ?: true
 
     val serializedIr =
         JsIrModuleSerializer(