diff --git a/idea/idea-completion/testData/basic/common/ExtensionToIntInFloatStyle.kt b/idea/idea-completion/testData/basic/common/ExtensionToIntInFloatStyle.kt
index 1a6e71869ff..323f0abc3a2 100644
--- a/idea/idea-completion/testData/basic/common/ExtensionToIntInFloatStyle.kt
+++ b/idea/idea-completion/testData/basic/common/ExtensionToIntInFloatStyle.kt
@@ -1,3 +1,5 @@
+// FIR_COMPARISON
+
 val Int.f: Float get() = this.toFloat()
 
 val test = 1.<caret>
diff --git a/idea/idea-completion/testData/basic/common/InFileWithTypedef.kt b/idea/idea-completion/testData/basic/common/InFileWithTypedef.kt
index 86abaeacc3c..269d3937498 100644
--- a/idea/idea-completion/testData/basic/common/InFileWithTypedef.kt
+++ b/idea/idea-completion/testData/basic/common/InFileWithTypedef.kt
@@ -1,3 +1,5 @@
+// FIR_COMPARISON
+
 class TestClassName
 type TestAlias = TestClassName
 
diff --git a/idea/idea-completion/testData/basic/common/InPropertyAccessor.kt b/idea/idea-completion/testData/basic/common/InPropertyAccessor.kt
index 3c554532f57..8a5c66461f9 100644
--- a/idea/idea-completion/testData/basic/common/InPropertyAccessor.kt
+++ b/idea/idea-completion/testData/basic/common/InPropertyAccessor.kt
@@ -1,3 +1,5 @@
+// FIR_COMPARISON
+
 class Foo(val a: Int, b: Int) {
     val e: Int
         get() = <caret>
diff --git a/idea/idea-completion/testData/basic/common/RecieverMembersFromExtAccessor.kt b/idea/idea-completion/testData/basic/common/RecieverMembersFromExtAccessor.kt
index 27581ec7530..db6e47f563e 100644
--- a/idea/idea-completion/testData/basic/common/RecieverMembersFromExtAccessor.kt
+++ b/idea/idea-completion/testData/basic/common/RecieverMembersFromExtAccessor.kt
@@ -1,3 +1,5 @@
+// FIR_COMPARISON
+
 class A {
     public fun foo(): Int = 1
     public val bar: Int = 1
diff --git a/idea/idea-completion/testData/basic/common/TypeArgCompletionBug.kt b/idea/idea-completion/testData/basic/common/TypeArgCompletionBug.kt
index 8dbf4a780a9..74d6eb413fa 100644
--- a/idea/idea-completion/testData/basic/common/TypeArgCompletionBug.kt
+++ b/idea/idea-completion/testData/basic/common/TypeArgCompletionBug.kt
@@ -1,3 +1,5 @@
+// FIR_COMPARISON
+
 interface FooBar1
 
 interface FooBar2 {
diff --git a/idea/idea-completion/testData/basic/common/TypeArgFromTheSameFile.kt b/idea/idea-completion/testData/basic/common/TypeArgFromTheSameFile.kt
index c50f3700093..3108ab55196 100644
--- a/idea/idea-completion/testData/basic/common/TypeArgFromTheSameFile.kt
+++ b/idea/idea-completion/testData/basic/common/TypeArgFromTheSameFile.kt
@@ -1,3 +1,5 @@
+// FIR_COMPARISON
+
 class C {
     val prop: List<F<caret>>
 }
diff --git a/idea/idea-completion/testData/basic/common/TypeArgOfOwnerClass.kt b/idea/idea-completion/testData/basic/common/TypeArgOfOwnerClass.kt
index 96aaa1d28d1..8770dd860a0 100644
--- a/idea/idea-completion/testData/basic/common/TypeArgOfOwnerClass.kt
+++ b/idea/idea-completion/testData/basic/common/TypeArgOfOwnerClass.kt
@@ -1,3 +1,5 @@
+// FIR_COMPARISON
+
 class C<TParam> {
     val v: List<T<caret>
 }
diff --git a/idea/idea-completion/testData/basic/common/TypeParameterFromOuterClass.kt b/idea/idea-completion/testData/basic/common/TypeParameterFromOuterClass.kt
index 783765a897c..73b7c7ee025 100644
--- a/idea/idea-completion/testData/basic/common/TypeParameterFromOuterClass.kt
+++ b/idea/idea-completion/testData/basic/common/TypeParameterFromOuterClass.kt
@@ -1,3 +1,5 @@
+// FIR_COMPARISON
+
 class X<T> {
     class Nested {
         val v: <caret>
diff --git a/idea/idea-completion/testData/basic/common/objects/PropertyFromCompanionObjectFromTypeAliasToNestedInObjectClass.kt b/idea/idea-completion/testData/basic/common/objects/PropertyFromCompanionObjectFromTypeAliasToNestedInObjectClass.kt
index 65e0e7d0c8e..c3c47cf14b8 100644
--- a/idea/idea-completion/testData/basic/common/objects/PropertyFromCompanionObjectFromTypeAliasToNestedInObjectClass.kt
+++ b/idea/idea-completion/testData/basic/common/objects/PropertyFromCompanionObjectFromTypeAliasToNestedInObjectClass.kt
@@ -1,3 +1,5 @@
+// FIR_COMPARISON
+
 object Obj {
     class NestedInObject {
         companion object {
diff --git a/idea/idea-completion/testData/basic/common/objects/PropertyOfTypeAliasToObject.kt b/idea/idea-completion/testData/basic/common/objects/PropertyOfTypeAliasToObject.kt
index 9be821ab1f1..86a5015e57c 100644
--- a/idea/idea-completion/testData/basic/common/objects/PropertyOfTypeAliasToObject.kt
+++ b/idea/idea-completion/testData/basic/common/objects/PropertyOfTypeAliasToObject.kt
@@ -1,3 +1,5 @@
+// FIR_COMPARISON
+
 object Obj {
     val inObject = 1
 }
diff --git a/idea/idea-completion/testData/basic/common/objects/TypeAliasToNestedObject.kt b/idea/idea-completion/testData/basic/common/objects/TypeAliasToNestedObject.kt
index 1e762885240..915d37fa387 100644
--- a/idea/idea-completion/testData/basic/common/objects/TypeAliasToNestedObject.kt
+++ b/idea/idea-completion/testData/basic/common/objects/TypeAliasToNestedObject.kt
@@ -1,3 +1,5 @@
+// FIR_COMPARISON
+
 class Cls {
     object Obj {
         val inObject = 1
diff --git a/idea/idea-completion/testData/basic/common/shadowing/InInitializer6.kt b/idea/idea-completion/testData/basic/common/shadowing/InInitializer6.kt
index 9222b5dfcae..3dd29084f1f 100644
--- a/idea/idea-completion/testData/basic/common/shadowing/InInitializer6.kt
+++ b/idea/idea-completion/testData/basic/common/shadowing/InInitializer6.kt
@@ -1,3 +1,5 @@
+// FIR_COMPARISON
+
 fun foo(p: () -> Unit): String = ""
 
 val xxx: String = foo { <caret> }
diff --git a/idea/idea-completion/testData/basic/java/NoSyntheticClasses.kt b/idea/idea-completion/testData/basic/java/NoSyntheticClasses.kt
index 5e00a4e8b71..12239599f0a 100644
--- a/idea/idea-completion/testData/basic/java/NoSyntheticClasses.kt
+++ b/idea/idea-completion/testData/basic/java/NoSyntheticClasses.kt
@@ -1,3 +1,5 @@
+// FIR_COMPARISON
+
 import kotlin.properties.*
 
 val x: ReadOnlyPr<caret>