diff --git a/compiler/testData/codegen/box/controlStructures/kt12908_2.kt b/compiler/testData/codegen/box/controlStructures/kt12908_2.kt
index 9e1de9c3e5d..a2a6d7fb28b 100644
--- a/compiler/testData/codegen/box/controlStructures/kt12908_2.kt
+++ b/compiler/testData/codegen/box/controlStructures/kt12908_2.kt
@@ -1,3 +1,4 @@
+// LANGUAGE: -ProhibitSimplificationOfNonTrivialConstBooleanExpressions
 // IGNORE_FIR_DIAGNOSTICS
 var field: Int = 0
 
diff --git a/compiler/testData/codegen/box/when/exhaustiveBoolean.kt b/compiler/testData/codegen/box/when/exhaustiveBoolean.kt
index 37432bf89f7..f7b35c3c30b 100644
--- a/compiler/testData/codegen/box/when/exhaustiveBoolean.kt
+++ b/compiler/testData/codegen/box/when/exhaustiveBoolean.kt
@@ -1,3 +1,4 @@
+// LANGUAGE: -ProhibitSimplificationOfNonTrivialConstBooleanExpressions
 // IGNORE_BACKEND_FIR: JVM_IR
 fun box() : String = when (true) {
     ((true)) -> "OK"