diff --git a/compiler/fir/raw-fir/light-tree2fir/src/org/jetbrains/kotlin/fir/lightTree/converter/ExpressionsConverter.kt b/compiler/fir/raw-fir/light-tree2fir/src/org/jetbrains/kotlin/fir/lightTree/converter/ExpressionsConverter.kt
index 5206f69492a..1f2985e33bb 100644
--- a/compiler/fir/raw-fir/light-tree2fir/src/org/jetbrains/kotlin/fir/lightTree/converter/ExpressionsConverter.kt
+++ b/compiler/fir/raw-fir/light-tree2fir/src/org/jetbrains/kotlin/fir/lightTree/converter/ExpressionsConverter.kt
@@ -267,6 +267,7 @@ class ExpressionsConverter(
                 }
                 explicitReceiver = leftArgAsFir
                 argumentList = buildUnaryArgumentList(rightArgAsFir)
+                origin = if (conventionCallName != null) FirFunctionCallOrigin.OPERATOR else FirFunctionCallOrigin.INFIX
             }
         } else {
             val firOperation = operationToken.toFirOperation()
diff --git a/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/call-with-trailing-lambda-expressions/p-1/pos/2.17.fir.kt b/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/call-with-trailing-lambda-expressions/p-1/pos/2.17.fir.kt
index 50e6e9a114b..5a3bc44c651 100644
--- a/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/call-with-trailing-lambda-expressions/p-1/pos/2.17.fir.kt
+++ b/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/call-with-trailing-lambda-expressions/p-1/pos/2.17.fir.kt
@@ -95,17 +95,17 @@ class A() {
 
     fun bar(a: A) {
         //todo: add info if function is infix one
-        <!DEBUG_INFO_CALL("fqName: testPackNew.A.foo; typeCall: function")!>a foo {1}<!>
+        <!DEBUG_INFO_CALL("fqName: testPackNew.A.foo; typeCall: infix extension function")!>a foo {1}<!>
     }
 
     fun buz(a: A) {
         fun foo(i: ()->Int) {}
         //todo: add info if function is infix one
-        <!DEBUG_INFO_CALL("fqName: testPackNew.A.foo; typeCall: function")!>a foo {1}<!>
+        <!DEBUG_INFO_CALL("fqName: testPackNew.A.foo; typeCall: infix extension function")!>a foo {1}<!>
     }
 
     fun boo(a: A) {
         infix fun A.foo(i: ()->Int) {}
-        <!DEBUG_INFO_CALL("fqName: testPackNew.A.foo; typeCall: function")!>a foo {1}<!>
+        <!DEBUG_INFO_CALL("fqName: testPackNew.A.boo.foo; typeCall: infix extension function")!>a foo {1}<!>
     }
 }
diff --git a/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/infix-function-call/p-2/neg/1.1.fir.kt b/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/infix-function-call/p-2/neg/1.1.fir.kt
index 2db48105ceb..7b808b81028 100644
--- a/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/infix-function-call/p-2/neg/1.1.fir.kt
+++ b/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/infix-function-call/p-2/neg/1.1.fir.kt
@@ -28,8 +28,8 @@ class Case1() {
 
     fun case1() {
         val a = A()
-        a foo 1
-        A() foo 1
+        a <!INFIX_MODIFIER_REQUIRED!>foo<!> 1
+        A() <!INFIX_MODIFIER_REQUIRED!>foo<!> 1
     }
 }
 // FILE: TestCase2.kt
@@ -43,8 +43,8 @@ interface Case2 {
 
     fun case2() {
         val a = A()
-        a foo 1
-        A() foo 1
+        a <!INFIX_MODIFIER_REQUIRED!>foo<!> 1
+        A() <!INFIX_MODIFIER_REQUIRED!>foo<!> 1
     }
 }
 
@@ -60,8 +60,8 @@ fun case3() {
     fun A.foo(x: Int) ="my local scope contains"
 
     val a = A()
-    a foo 1
-    A() foo 1
+    a <!INFIX_MODIFIER_REQUIRED!>foo<!> 1
+    A() <!INFIX_MODIFIER_REQUIRED!>foo<!> 1
 }
 
 // FILE: TestCase4.kt
@@ -79,7 +79,7 @@ fun case4() {
     fun subfun() {
         fun A.foo(x: Int) = "my local contains"
         val a = A()
-        a foo 1
-        A() foo 1
+        a <!INFIX_MODIFIER_REQUIRED!>foo<!> 1
+        A() <!INFIX_MODIFIER_REQUIRED!>foo<!> 1
     }
 }
diff --git a/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/infix-function-call/p-2/neg/1.2.fir.kt b/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/infix-function-call/p-2/neg/1.2.fir.kt
index 091876b7dc3..89614af245d 100644
--- a/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/infix-function-call/p-2/neg/1.2.fir.kt
+++ b/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/infix-function-call/p-2/neg/1.2.fir.kt
@@ -32,7 +32,7 @@ class Case1() {
 
     fun case1() {
         val regex = Regex("")
-        "" contains regex
+        "" <!INFIX_MODIFIER_REQUIRED!>contains<!> regex
     }
 }
 // FILE: TestCase2.kt
@@ -49,7 +49,7 @@ interface Case2 {
 
     fun case2() {
         val regex = Regex("")
-        "" contains regex
+        "" <!INFIX_MODIFIER_REQUIRED!>contains<!> regex
     }
 }
 
@@ -70,7 +70,7 @@ fun case3() {
     }
 
     val regex = Regex("")
-    "" contains regex
+    "" <!INFIX_MODIFIER_REQUIRED!>contains<!> regex
 }
 
 // FILE: TestCase4.kt
@@ -98,7 +98,7 @@ fun case4() {
         }
 
         val regex = Regex("")
-        "" contains regex
+        "" <!INFIX_MODIFIER_REQUIRED!>contains<!> regex
 
     }
 }
diff --git a/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/infix-function-call/p-2/neg/1.3.fir.kt b/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/infix-function-call/p-2/neg/1.3.fir.kt
index 53efae4a21c..05a36a21622 100644
--- a/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/infix-function-call/p-2/neg/1.3.fir.kt
+++ b/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/infix-function-call/p-2/neg/1.3.fir.kt
@@ -27,7 +27,7 @@ import libPackage.contains
 
 fun case1() {
     val regex = Regex("")
-   "" contains  regex
+   "" <!INFIX_MODIFIER_REQUIRED!>contains<!>  regex
 }
 
 // FILE: TestCase2.kt
@@ -44,5 +44,6 @@ fun case2() {
     }
 
     val regex = Regex("")
-    "" contains  regex
+    "" <!INFIX_MODIFIER_REQUIRED!>contains<!>  regex
 }
+
diff --git a/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/infix-function-call/p-2/neg/1.4.fir.kt b/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/infix-function-call/p-2/neg/1.4.fir.kt
index 6f9e36c7b56..0c2db1cd175 100644
--- a/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/infix-function-call/p-2/neg/1.4.fir.kt
+++ b/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/infix-function-call/p-2/neg/1.4.fir.kt
@@ -27,7 +27,7 @@ import libPackage.*
 
 fun case1() {
     val regex = Regex("")
-   "" contains  regex
+   "" <!INFIX_MODIFIER_REQUIRED!>contains<!>  regex
 }
 
 // FILE: TestCase2.kt
@@ -42,5 +42,5 @@ import libPackage.*
 
 fun case2() {
     val regex = Regex("")
-    "" contains  regex
+    "" <!INFIX_MODIFIER_REQUIRED!>contains<!>  regex
 }
diff --git a/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/infix-function-call/p-2/neg/4.5.fir.kt b/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/infix-function-call/p-2/neg/4.5.fir.kt
index aff935d8a7f..39608866ff9 100644
--- a/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/infix-function-call/p-2/neg/4.5.fir.kt
+++ b/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/infix-function-call/p-2/neg/4.5.fir.kt
@@ -17,5 +17,5 @@ import libPackage.* //nothing to import, extension is private
 // TESTCASE NUMBER: 1
 fun case1() {
     val regex = Regex("")
-    "" contains regex
+    "" <!INFIX_MODIFIER_REQUIRED!>contains<!> regex
 }
diff --git a/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/infix-function-call/p-2/pos/4.1.fir.kt b/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/infix-function-call/p-2/pos/4.1.fir.kt
index 655c5b7cd1b..84b861afaa5 100644
--- a/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/infix-function-call/p-2/pos/4.1.fir.kt
+++ b/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/infix-function-call/p-2/pos/4.1.fir.kt
@@ -94,17 +94,17 @@ class A() {
 
     fun bar(a: A) {
         //todo: add info if function is infix one
-       <!DEBUG_INFO_CALL("fqName: testPackNew.A.foo; typeCall: function")!>a foo 1<!>
+       <!DEBUG_INFO_CALL("fqName: testPackNew.A.foo; typeCall: infix extension function")!>a foo 1<!>
     }
 
     fun buz(a: A){
         fun foo(i: Int) {}
         //todo: add info if function is infix one
-        <!DEBUG_INFO_CALL("fqName: testPackNew.A.foo; typeCall: function")!>a foo 1<!>
+        <!DEBUG_INFO_CALL("fqName: testPackNew.A.foo; typeCall: infix extension function")!>a foo 1<!>
     }
 
     fun boo(a: A){
         infix fun A.foo(i: Int) {}
-        <!DEBUG_INFO_CALL("fqName: testPackNew.A.foo; typeCall: function")!>a foo 1<!>
+        <!DEBUG_INFO_CALL("fqName: testPackNew.A.boo.foo; typeCall: infix extension function")!>a foo 1<!>
     }
 }
diff --git a/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/operator-call/p-2/pos/3.3.fir.kt b/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/operator-call/p-2/pos/3.3.fir.kt
index 2c81293510a..6bfb0d8bf7b 100644
--- a/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/operator-call/p-2/pos/3.3.fir.kt
+++ b/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/operator-call/p-2/pos/3.3.fir.kt
@@ -55,9 +55,9 @@ class Case() {
         /*operator*/ fun E.plus(value: Int) = Case()
 
         run {
-            <!DEBUG_INFO_CALL("fqName: testPackCase1.Case.E.plus; typeCall: function")!>e + 1<!>
+            <!DEBUG_INFO_CALL("fqName: libPackage1.plus; typeCall: operator extension function")!>e + 1<!>
         }
-        <!DEBUG_INFO_CALL("fqName: testPackCase1.Case.E.plus; typeCall: function")!>e + 1<!>
+        <!DEBUG_INFO_CALL("fqName: libPackage1.plus; typeCall: operator extension function")!>e + 1<!>
 
     }
 }
@@ -105,9 +105,9 @@ class Case() {
         run {
             /*operator*/ fun E.plus(value: Int) = Case()
 
-            <!DEBUG_INFO_CALL("fqName: testPackCase2.Case.E.plus; typeCall: function")!>e + 1<!>
+            <!DEBUG_INFO_CALL("fqName: libPackage1.plus; typeCall: operator extension function")!>e + 1<!>
         }
-        <!DEBUG_INFO_CALL("fqName: testPackCase2.Case.E.plus; typeCall: function")!>e + 1<!>
+        <!DEBUG_INFO_CALL("fqName: libPackage1.plus; typeCall: operator extension function")!>e + 1<!>
     }
 }
 
diff --git a/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/operator-call/p-2/pos/3.4.fir.kt b/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/operator-call/p-2/pos/3.4.fir.kt
index 2fd586d2d0f..f0fe20740d3 100644
--- a/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/operator-call/p-2/pos/3.4.fir.kt
+++ b/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/operator-call/p-2/pos/3.4.fir.kt
@@ -46,9 +46,9 @@ class Case() {
         /*operator*/ fun E.plus(value: Int) = Case()
 
         run {
-            <!DEBUG_INFO_CALL("fqName: testPackCase1.Case.E.plus; typeCall: function")!>e + 1<!>
+            <!DEBUG_INFO_CALL("fqName: testPackCase1.plus; typeCall: operator extension function")!>e + 1<!>
         }
-        <!DEBUG_INFO_CALL("fqName: testPackCase1.Case.E.plus; typeCall: function")!>e + 1<!>
+        <!DEBUG_INFO_CALL("fqName: testPackCase1.plus; typeCall: operator extension function")!>e + 1<!>
 
     }
 }
@@ -97,9 +97,9 @@ class Case() {
         run {
             /*operator*/ fun E.plus(value: Int) = Case()
 
-            <!DEBUG_INFO_CALL("fqName: testPackCase2.Case.E.plus; typeCall: function")!>e + 1<!>
+            <!DEBUG_INFO_CALL("fqName: testPackCase2.plus; typeCall: operator extension function")!>e + 1<!>
         }
-        <!DEBUG_INFO_CALL("fqName: testPackCase2.Case.E.plus; typeCall: function")!>e + 1<!>
+        <!DEBUG_INFO_CALL("fqName: testPackCase2.plus; typeCall: operator extension function")!>e + 1<!>
     }
 }
 
diff --git a/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/operator-call/p-2/pos/3.5.fir.kt b/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/operator-call/p-2/pos/3.5.fir.kt
index e2a605db535..95e9ea5f1e4 100644
--- a/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/operator-call/p-2/pos/3.5.fir.kt
+++ b/compiler/tests-spec/testData/diagnostics/linked/overload-resolution/building-the-overload-candidate-set-ocs/operator-call/p-2/pos/3.5.fir.kt
@@ -43,9 +43,9 @@ class Case() {
         /*operator*/ fun E.plus(value: Int) = Case()
 
         run {
-            <!DEBUG_INFO_CALL("fqName: testPackCase1.Case.E.plus; typeCall: function")!>e + 1<!>
+            <!DEBUG_INFO_CALL("fqName: libPackage.plus; typeCall: operator extension function")!>e + 1<!>
         }
-        <!DEBUG_INFO_CALL("fqName: testPackCase1.Case.E.plus; typeCall: function")!>e + 1<!>
+        <!DEBUG_INFO_CALL("fqName: libPackage.plus; typeCall: operator extension function")!>e + 1<!>
 
     }
 }