diff --git a/compiler/testData/diagnostics/tests/constantEvaluator/constant/compareTo.fir.kt b/compiler/testData/diagnostics/tests/constantEvaluator/constant/compareTo.fir.kt
index 15fde0e67e5..e337f04663e 100644
--- a/compiler/testData/diagnostics/tests/constantEvaluator/constant/compareTo.fir.kt
+++ b/compiler/testData/diagnostics/tests/constantEvaluator/constant/compareTo.fir.kt
@@ -1,3 +1,4 @@
+// !LANGUAGE: -ProhibitSimplificationOfNonTrivialConstBooleanExpressions
 package test
 
 // val prop1: false
diff --git a/compiler/testData/diagnostics/tests/constantEvaluator/constant/compareTo.kt b/compiler/testData/diagnostics/tests/constantEvaluator/constant/compareTo.kt
index 73ddcb26023..7e1c25decc3 100644
--- a/compiler/testData/diagnostics/tests/constantEvaluator/constant/compareTo.kt
+++ b/compiler/testData/diagnostics/tests/constantEvaluator/constant/compareTo.kt
@@ -1,3 +1,4 @@
+// !LANGUAGE: -ProhibitSimplificationOfNonTrivialConstBooleanExpressions
 package test
 
 // val prop1: false
diff --git a/compiler/testData/diagnostics/tests/constantEvaluator/constant/equals.fir.kt b/compiler/testData/diagnostics/tests/constantEvaluator/constant/equals.fir.kt
index 285f7df03f0..a30b6f3801f 100644
--- a/compiler/testData/diagnostics/tests/constantEvaluator/constant/equals.fir.kt
+++ b/compiler/testData/diagnostics/tests/constantEvaluator/constant/equals.fir.kt
@@ -1,3 +1,4 @@
+// !LANGUAGE: -ProhibitSimplificationOfNonTrivialConstBooleanExpressions
 package test
 
 // val prop4: true
diff --git a/compiler/testData/diagnostics/tests/constantEvaluator/constant/equals.kt b/compiler/testData/diagnostics/tests/constantEvaluator/constant/equals.kt
index 5e50bbeb515..d6c0cb9c5f2 100644
--- a/compiler/testData/diagnostics/tests/constantEvaluator/constant/equals.kt
+++ b/compiler/testData/diagnostics/tests/constantEvaluator/constant/equals.kt
@@ -1,3 +1,4 @@
+// !LANGUAGE: -ProhibitSimplificationOfNonTrivialConstBooleanExpressions
 package test
 
 // val prop4: true
diff --git a/compiler/testData/diagnostics/tests/constantEvaluator/usesVariableAsConstant/binaryTypes.fir.kt b/compiler/testData/diagnostics/tests/constantEvaluator/usesVariableAsConstant/binaryTypes.fir.kt
index 26153535d61..3a4a5d47813 100644
--- a/compiler/testData/diagnostics/tests/constantEvaluator/usesVariableAsConstant/binaryTypes.fir.kt
+++ b/compiler/testData/diagnostics/tests/constantEvaluator/usesVariableAsConstant/binaryTypes.fir.kt
@@ -1,3 +1,4 @@
+// !LANGUAGE: -ProhibitSimplificationOfNonTrivialConstBooleanExpressions
 package test
 
 val x = 1
diff --git a/compiler/testData/diagnostics/tests/constantEvaluator/usesVariableAsConstant/binaryTypes.kt b/compiler/testData/diagnostics/tests/constantEvaluator/usesVariableAsConstant/binaryTypes.kt
index 5aae33a4f95..7a4709a755d 100644
--- a/compiler/testData/diagnostics/tests/constantEvaluator/usesVariableAsConstant/binaryTypes.kt
+++ b/compiler/testData/diagnostics/tests/constantEvaluator/usesVariableAsConstant/binaryTypes.kt
@@ -1,3 +1,4 @@
+// !LANGUAGE: -ProhibitSimplificationOfNonTrivialConstBooleanExpressions
 package test
 
 val x = 1