diff --git a/compiler/fir/analysis-tests/testData/resolve/expresssions/invoke/implicitTypeOrder.fir.txt b/compiler/fir/analysis-tests/testData/resolve/expresssions/invoke/implicitTypeOrder.fir.txt
index 122a093634f..ba91fae59bd 100644
--- a/compiler/fir/analysis-tests/testData/resolve/expresssions/invoke/implicitTypeOrder.fir.txt
+++ b/compiler/fir/analysis-tests/testData/resolve/expresssions/invoke/implicitTypeOrder.fir.txt
@@ -5,7 +5,7 @@ FILE: implicitTypeOrder.kt
         }
 
         public final fun bar(): R|A| {
-            ^bar R|/foo|.R|/A.invoke|()
+            ^bar R|/foo|.<Inapplicable(INAPPLICABLE_MODIFIER): /A.invoke>#()
         }
 
         public final fun invoke(): R|A| {
diff --git a/compiler/fir/analysis-tests/testData/resolve/expresssions/invoke/implicitTypeOrder.kt b/compiler/fir/analysis-tests/testData/resolve/expresssions/invoke/implicitTypeOrder.kt
index 713e35a3dda..e27f1db2ad4 100644
--- a/compiler/fir/analysis-tests/testData/resolve/expresssions/invoke/implicitTypeOrder.kt
+++ b/compiler/fir/analysis-tests/testData/resolve/expresssions/invoke/implicitTypeOrder.kt
@@ -1,6 +1,6 @@
 
 class A {
-    fun bar() = foo() // should resolve to invoke
+    fun bar() = <!OPERATOR_MODIFIER_REQUIRED!>foo<!>() // should resolve to invoke
 
     fun invoke() = this
 }
diff --git a/compiler/fir/analysis-tests/testData/resolve/qualifierWithCompanion.fir.txt b/compiler/fir/analysis-tests/testData/resolve/qualifierWithCompanion.fir.txt
index 7bd638708f8..c9abb3485b0 100644
--- a/compiler/fir/analysis-tests/testData/resolve/qualifierWithCompanion.fir.txt
+++ b/compiler/fir/analysis-tests/testData/resolve/qualifierWithCompanion.fir.txt
@@ -24,5 +24,5 @@ FILE: qualifierWithCompanion.kt
         local final fun R|my/A|.invoke(): R|kotlin/Unit| {
         }
 
-        Q|my|.R|my/xx|.R|<local>/invoke|()
+        Q|my|.R|my/xx|.<Inapplicable(INAPPLICABLE_MODIFIER): <local>/invoke>#()
     }
diff --git a/compiler/fir/analysis-tests/testData/resolve/qualifierWithCompanion.kt b/compiler/fir/analysis-tests/testData/resolve/qualifierWithCompanion.kt
index 102fe6387d2..c1239ed03b6 100644
--- a/compiler/fir/analysis-tests/testData/resolve/qualifierWithCompanion.kt
+++ b/compiler/fir/analysis-tests/testData/resolve/qualifierWithCompanion.kt
@@ -15,5 +15,5 @@ fun test() {
 
     fun A.invoke() {}
 
-    my.xx()
+    my.<!OPERATOR_MODIFIER_REQUIRED!>xx<!>()
 }
diff --git a/compiler/testData/diagnostics/tests/j+k/collectionOverrides/irrelevantImplMutableListKotlin.fir.kt b/compiler/testData/diagnostics/tests/j+k/collectionOverrides/irrelevantImplMutableListKotlin.fir.kt
index 394926bd709..7a1d20c36df 100644
--- a/compiler/testData/diagnostics/tests/j+k/collectionOverrides/irrelevantImplMutableListKotlin.fir.kt
+++ b/compiler/testData/diagnostics/tests/j+k/collectionOverrides/irrelevantImplMutableListKotlin.fir.kt
@@ -99,7 +99,6 @@ public class A extends AImpl implements List<String> {
 
 fun main() {
     val x = X()
-    //todo get only one candidate - AImpl.get, no kotlin.collection.List for some reason
     <!OPERATOR_MODIFIER_REQUIRED!>x[0]<!>
     x.size
     x.remove("")
diff --git a/compiler/testData/diagnostics/tests/operatorsOverloading/kt11300.fir.kt b/compiler/testData/diagnostics/tests/operatorsOverloading/kt11300.fir.kt
index 0d1ef4a52ad..bf731458499 100644
--- a/compiler/testData/diagnostics/tests/operatorsOverloading/kt11300.fir.kt
+++ b/compiler/testData/diagnostics/tests/operatorsOverloading/kt11300.fir.kt
@@ -8,8 +8,6 @@ class A {
 fun main() {
     val a = A()
     <!OPERATOR_MODIFIER_REQUIRED!>a[1]<!>++
-    //fir prefers plusAssign call if neither get+set nor plusAssign resolverd
-    //hence UNRESOLVED_REFERENCE here
     a[1] <!UNRESOLVED_REFERENCE!>+=<!> 3
     <!OPERATOR_MODIFIER_REQUIRED!>a[1]<!> = a[1] + 3
 }
diff --git a/compiler/tests-spec/testData/diagnostics/linked/expressions/comparison-expressions/p-1/neg/2.1.fir.kt b/compiler/tests-spec/testData/diagnostics/linked/expressions/comparison-expressions/p-1/neg/2.1.fir.kt
index 65a612bf9e9..c9031ae14e1 100644
--- a/compiler/tests-spec/testData/diagnostics/linked/expressions/comparison-expressions/p-1/neg/2.1.fir.kt
+++ b/compiler/tests-spec/testData/diagnostics/linked/expressions/comparison-expressions/p-1/neg/2.1.fir.kt
@@ -13,5 +13,5 @@ fun case1() {
     val a3 = A(-1)
     val a4 = A(-3)
 
-    val x = (a3 > a4)
+    val x = (a3 <!OPERATOR_MODIFIER_REQUIRED!>><!> a4)
 }
diff --git a/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/call-without-an-explicit-receiver/p-5/neg/4.2.fir.kt b/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/call-without-an-explicit-receiver/p-5/neg/4.2.fir.kt
index 4a1f13cdafc..8408260589a 100644
--- a/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/call-without-an-explicit-receiver/p-5/neg/4.2.fir.kt
+++ b/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/call-without-an-explicit-receiver/p-5/neg/4.2.fir.kt
@@ -16,8 +16,8 @@ interface I
 class B : I
 
 fun case1(){
-    <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Int")!>A()<!>
-    <!DEBUG_INFO_CALL("fqName: lib.case1.A.invoke; typeCall: variable&invoke")!>A()<!>
+    <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Int")!><!OPERATOR_MODIFIER_REQUIRED!>A<!>()<!>
+    <!DEBUG_INFO_CALL("fqName: fqName is unknown; typeCall: unresolved")!><!OPERATOR_MODIFIER_REQUIRED!>A<!>()<!>
 }
 
 // FILE: Lib.kt
diff --git a/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/call-without-an-explicit-receiver/p-5/pos/4.2.fir.kt b/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/call-without-an-explicit-receiver/p-5/pos/4.2.fir.kt
index 54540ed5157..033194a1093 100644
--- a/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/call-without-an-explicit-receiver/p-5/pos/4.2.fir.kt
+++ b/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/call-without-an-explicit-receiver/p-5/pos/4.2.fir.kt
@@ -71,8 +71,8 @@ class A : I
 class B : I
 
 fun case3(){
-    <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Int")!>A()<!>
-    <!DEBUG_INFO_CALL("fqName: lib.case3.A.invoke; typeCall: variable&invoke")!>A()<!>
+    <!DEBUG_INFO_EXPRESSION_TYPE("tests.case3.A")!>A()<!>
+    <!DEBUG_INFO_CALL("fqName: tests.case3.A.A; typeCall: function")!>A()<!>
 
     A.invoke()
     A.<!DEBUG_INFO_CALL("fqName: lib.case3.A.invoke; typeCall: function")!>invoke()<!>
diff --git a/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/call-without-an-explicit-receiver/p-5/pos/4.5.fir.kt b/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/call-without-an-explicit-receiver/p-5/pos/4.5.fir.kt
index 10cf0efb228..b4d793e0591 100644
--- a/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/call-without-an-explicit-receiver/p-5/pos/4.5.fir.kt
+++ b/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/call-without-an-explicit-receiver/p-5/pos/4.5.fir.kt
@@ -71,8 +71,8 @@ class A : I
 class B : I
 
 fun case3(){
-    <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Int")!>A()<!>
-    <!DEBUG_INFO_CALL("fqName: lib.case3.B.invoke; typeCall: variable&invoke")!>A()<!>
+    <!DEBUG_INFO_EXPRESSION_TYPE("tests.case3.A")!>A()<!>
+    <!DEBUG_INFO_CALL("fqName: tests.case3.A.A; typeCall: function")!>A()<!>
 
     A.invoke()
     A.<!DEBUG_INFO_CALL("fqName: lib.case3.B.invoke; typeCall: function")!>invoke()<!>
diff --git a/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/call-without-an-explicit-receiver/p-5/pos/4.6.fir.kt b/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/call-without-an-explicit-receiver/p-5/pos/4.6.fir.kt
index d85fea04ffe..36d98e3d733 100644
--- a/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/call-without-an-explicit-receiver/p-5/pos/4.6.fir.kt
+++ b/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/call-without-an-explicit-receiver/p-5/pos/4.6.fir.kt
@@ -91,14 +91,14 @@ class A : I
 class B : I
 
 fun case3(){
-    <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Int")!>A()<!>
-    <!DEBUG_INFO_CALL("fqName: lib.case3.a.C.invoke; typeCall: variable&invoke")!>A()<!>
+    <!DEBUG_INFO_EXPRESSION_TYPE("tests.case3.A")!>A()<!>
+    <!DEBUG_INFO_CALL("fqName: tests.case3.A.A; typeCall: function")!>A()<!>
 
     A.invoke()
     A.<!DEBUG_INFO_CALL("fqName: lib.case3.a.C.invoke; typeCall: function")!>invoke()<!>
 
-    <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Int")!>B()<!>
-    <!DEBUG_INFO_CALL("fqName: lib.case3.b.C.invoke; typeCall: variable&invoke")!>B()<!>
+    <!DEBUG_INFO_EXPRESSION_TYPE("tests.case3.B")!>B()<!>
+    <!DEBUG_INFO_CALL("fqName: tests.case3.B.B; typeCall: function")!>B()<!>
 
     B.invoke()
     B.<!DEBUG_INFO_CALL("fqName: lib.case3.b.C.invoke; typeCall: function")!>invoke()<!>
diff --git a/idea/testData/resolve/references/delegatedPropertyAccessors/inSource/getExtension.kt b/idea/testData/resolve/references/delegatedPropertyAccessors/inSource/getExtension.kt
index 94c7a250a24..92bace65966 100644
--- a/idea/testData/resolve/references/delegatedPropertyAccessors/inSource/getExtension.kt
+++ b/idea/testData/resolve/references/delegatedPropertyAccessors/inSource/getExtension.kt
@@ -2,7 +2,7 @@ val x: Int <caret>by Foo()
 
 class Foo
 
-fun Foo.getValue(_this: Any?, p: Any?): Int = 1
+operator fun Foo.getValue(_this: Any?, p: Any?): Int = 1
 
 // REF: (for Foo in <root>).getValue(Any?, Any?)
 
diff --git a/idea/testData/resolve/references/delegatedPropertyAccessors/inSource/getMember.kt b/idea/testData/resolve/references/delegatedPropertyAccessors/inSource/getMember.kt
index e074e1a5fd3..6a99b21587c 100644
--- a/idea/testData/resolve/references/delegatedPropertyAccessors/inSource/getMember.kt
+++ b/idea/testData/resolve/references/delegatedPropertyAccessors/inSource/getMember.kt
@@ -1,7 +1,7 @@
 val x: Int <caret>by Foo()
 
 class Foo {
-    fun getValue(_this: Any?, p: Any?): Int = 1
+    operator fun getValue(_this: Any?, p: Any?): Int = 1
 }
 
 // REF: (in Foo).getValue(Any?, Any?)
diff --git a/idea/testData/resolve/references/delegatedPropertyAccessors/inSource/getMultipleDeclarations.kt b/idea/testData/resolve/references/delegatedPropertyAccessors/inSource/getMultipleDeclarations.kt
index 8c0fe7a2657..f4b7b2a0338 100644
--- a/idea/testData/resolve/references/delegatedPropertyAccessors/inSource/getMultipleDeclarations.kt
+++ b/idea/testData/resolve/references/delegatedPropertyAccessors/inSource/getMultipleDeclarations.kt
@@ -1,15 +1,15 @@
 var x : Int <caret>by Baz()
 
 interface Foo {
-  fun getValue(p1: Any?, p2: Any?): Int = 1
+  operator fun getValue(p1: Any?, p2: Any?): Int = 1
 }
 
 interface Bar {
-  fun getValue(p1: Any?, p2: Any?): Int
+  operator fun getValue(p1: Any?, p2: Any?): Int
 }
 
 interface Zoo {
-  fun setValue(p1: Any?, p2: Any?, p3: Any?)
+  operator fun setValue(p1: Any?, p2: Any?, p3: Any?)
 }
 
 class Baz: Foo, Bar, Zoo
diff --git a/idea/testData/resolve/references/delegatedPropertyAccessors/inSource/getOneFakeOverride.kt b/idea/testData/resolve/references/delegatedPropertyAccessors/inSource/getOneFakeOverride.kt
index 6123017e9ee..eade248e5f2 100644
--- a/idea/testData/resolve/references/delegatedPropertyAccessors/inSource/getOneFakeOverride.kt
+++ b/idea/testData/resolve/references/delegatedPropertyAccessors/inSource/getOneFakeOverride.kt
@@ -1,7 +1,7 @@
 var x : Int <caret>by Baz()
 
 interface Foo {
-  fun getValue(p1: Any?, p2: Any?): Int = 1
+  operator fun getValue(p1: Any?, p2: Any?): Int = 1
 }
 
 class Baz: Foo