diff --git a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/dfa/FirDataFlowAnalyzer.kt b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/dfa/FirDataFlowAnalyzer.kt
index d9e60c1ffc9..ed85fb7acba 100644
--- a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/dfa/FirDataFlowAnalyzer.kt
+++ b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/dfa/FirDataFlowAnalyzer.kt
@@ -390,7 +390,7 @@ abstract class FirDataFlowAnalyzer<FLOW : Flow>(
         when (val operation = typeOperatorCall.operation) {
             FirOperation.IS, FirOperation.NOT_IS -> {
                 val expressionVariable = variableStorage.createSyntheticVariable(typeOperatorCall)
-                val isNotNullCheck = type.nullability == ConeNullability.NOT_NULL
+                val isNotNullCheck = !type.canBeNull
                 val isRegularIs = operation == FirOperation.IS
                 if (operandVariable.isReal()) {
                     val hasTypeInfo = operandVariable typeEq type
diff --git a/compiler/testData/diagnostics/tests/generics/nullability/considerTypeNotNullOnlyIfItHasNotNullBound.fir.kt b/compiler/testData/diagnostics/tests/generics/nullability/considerTypeNotNullOnlyIfItHasNotNullBound.fir.kt
index cd7358e05ac..4a94cf70a71 100644
--- a/compiler/testData/diagnostics/tests/generics/nullability/considerTypeNotNullOnlyIfItHasNotNullBound.fir.kt
+++ b/compiler/testData/diagnostics/tests/generics/nullability/considerTypeNotNullOnlyIfItHasNotNullBound.fir.kt
@@ -1,6 +1,6 @@
 // !LANGUAGE: +NewInference
 
 inline fun <T, reified S> foo(x: T?, y: T): T {
-    if (x is S) return x
+    if (x is S) return <!RETURN_TYPE_MISMATCH!>x<!>
     return y
 }
diff --git a/compiler/testData/diagnostics/tests/smartCasts/safecalls/safeAccessReceiverNotNull.fir.kt b/compiler/testData/diagnostics/tests/smartCasts/safecalls/safeAccessReceiverNotNull.fir.kt
index 35f672f1bd2..0dfb36ce12f 100644
--- a/compiler/testData/diagnostics/tests/smartCasts/safecalls/safeAccessReceiverNotNull.fir.kt
+++ b/compiler/testData/diagnostics/tests/smartCasts/safecalls/safeAccessReceiverNotNull.fir.kt
@@ -67,6 +67,24 @@ fun kt4565_2(a: SomeClass?) {
     }
 }
 
+inline fun <reified T : SomeClass> kt45345(a: SomeClass?) {
+    if (a?.data is T) {
+        a.data
+    }
+}
+
+inline fun <reified T : U, U : SomeClass> kt45345_2(a: SomeClass?) {
+    if (a?.data is T) {
+        a.data
+    }
+}
+
+inline fun <reified T : U, U : SomeClass?> kt45345_3(a: SomeClass?) {
+    if (a?.data is T) {
+        a<!UNSAFE_CALL!>.<!>data
+    }
+}
+
 class A(val y: Int)
 
 fun kt7491_1() {
diff --git a/compiler/testData/diagnostics/tests/smartCasts/safecalls/safeAccessReceiverNotNull.kt b/compiler/testData/diagnostics/tests/smartCasts/safecalls/safeAccessReceiverNotNull.kt
index 13f79d76f0d..c884bacb6f2 100644
--- a/compiler/testData/diagnostics/tests/smartCasts/safecalls/safeAccessReceiverNotNull.kt
+++ b/compiler/testData/diagnostics/tests/smartCasts/safecalls/safeAccessReceiverNotNull.kt
@@ -67,6 +67,24 @@ fun kt4565_2(a: SomeClass?) {
     }
 }
 
+inline fun <reified T : SomeClass> kt45345(a: SomeClass?) {
+    if (a?.data is T) {
+        <!DEBUG_INFO_SMARTCAST!>a<!>.data
+    }
+}
+
+inline fun <reified T : U, U : SomeClass> kt45345_2(a: SomeClass?) {
+    if (a?.data is T) {
+        <!DEBUG_INFO_SMARTCAST!>a<!>.data
+    }
+}
+
+inline fun <reified T : U, U : SomeClass?> kt45345_3(a: SomeClass?) {
+    if (a?.data is T) {
+        a<!UNSAFE_CALL!>.<!>data
+    }
+}
+
 class A(val y: Int)
 
 fun kt7491_1() {
diff --git a/compiler/testData/diagnostics/tests/smartCasts/safecalls/safeAccessReceiverNotNull.txt b/compiler/testData/diagnostics/tests/smartCasts/safecalls/safeAccessReceiverNotNull.txt
index ca0619071bf..888f291b963 100644
--- a/compiler/testData/diagnostics/tests/smartCasts/safecalls/safeAccessReceiverNotNull.txt
+++ b/compiler/testData/diagnostics/tests/smartCasts/safecalls/safeAccessReceiverNotNull.txt
@@ -10,6 +10,9 @@ public fun kt11313(/*0*/ arg: HttpExchange?): kotlin.Unit
 public fun kt1635(/*0*/ s: kotlin.String?): kotlin.Unit
 public fun kt2127(): kotlin.Unit
 public fun kt3356(/*0*/ s: kotlin.String?): kotlin.Int
+public inline fun </*0*/ reified T : SomeClass> kt45345(/*0*/ a: SomeClass?): kotlin.Unit
+public inline fun </*0*/ reified T : U, /*1*/ U : SomeClass> kt45345_2(/*0*/ a: SomeClass?): kotlin.Unit
+public inline fun </*0*/ reified T : U, /*1*/ U : SomeClass?> kt45345_3(/*0*/ a: SomeClass?): kotlin.Unit
 public fun kt4565_1(/*0*/ a: SomeClass?): kotlin.Unit
 public fun kt4565_2(/*0*/ a: SomeClass?): kotlin.Unit
 public fun kt6840_1(/*0*/ s: kotlin.String?): kotlin.Unit
diff --git a/compiler/tests-spec/testData/diagnostics/linked/type-system/type-contexts-and-scopes/inner-and-nested-type-contexts/p-1/pos/1.1.fir.kt b/compiler/tests-spec/testData/diagnostics/linked/type-system/type-contexts-and-scopes/inner-and-nested-type-contexts/p-1/pos/1.1.fir.kt
index d3f5851c91e..8f50f965e0d 100644
--- a/compiler/tests-spec/testData/diagnostics/linked/type-system/type-contexts-and-scopes/inner-and-nested-type-contexts/p-1/pos/1.1.fir.kt
+++ b/compiler/tests-spec/testData/diagnostics/linked/type-system/type-contexts-and-scopes/inner-and-nested-type-contexts/p-1/pos/1.1.fir.kt
@@ -22,7 +22,7 @@ class Case1<AT>(val x: AT) {
 
             when (k) {
                 is AT -> {
-                    k checkType { <!NONE_APPLICABLE!>check<!><AT>() }
+                    k checkType { check<AT>() }
                 }
             }
         }
@@ -31,7 +31,7 @@ class Case1<AT>(val x: AT) {
             val k: AT = x!!
 
             if (k is AT) {
-                k checkType { <!NONE_APPLICABLE!>check<!><AT>() }
+                k checkType { check<AT>() }
             }
         }
     }
diff --git a/compiler/tests-spec/testData/diagnostics/notLinked/dfa/neg/23.fir.kt b/compiler/tests-spec/testData/diagnostics/notLinked/dfa/neg/23.fir.kt
index 7aa1e2cb1fb..de3388e7195 100644
--- a/compiler/tests-spec/testData/diagnostics/notLinked/dfa/neg/23.fir.kt
+++ b/compiler/tests-spec/testData/diagnostics/notLinked/dfa/neg/23.fir.kt
@@ -8,8 +8,8 @@
  */
 inline fun <reified T, reified K> case_1(x: T) {
     if (x is K) {
-        <!DEBUG_INFO_EXPRESSION_TYPE("T & K!! & T!!")!>x<!>
-        <!DEBUG_INFO_EXPRESSION_TYPE("T & K!! & T!!")!>x<!>.equals(x)
+        <!DEBUG_INFO_EXPRESSION_TYPE("T & K & T")!>x<!>
+        <!DEBUG_INFO_EXPRESSION_TYPE("T & K & T")!>x<!><!UNSAFE_CALL!>.<!>equals(x)
     }
 }
 
@@ -31,8 +31,8 @@ inline fun <reified T, reified K> case_3() {
     var x: T? = 10 as T
     x = null
     if (x is K) {
-        <!DEBUG_INFO_EXPRESSION_TYPE("T? & kotlin.Nothing")!>x<!>.equals(10)
-        <!DEBUG_INFO_EXPRESSION_TYPE("T? & kotlin.Nothing")!>x<!>
+        <!DEBUG_INFO_EXPRESSION_TYPE("T? & kotlin.Nothing? & K")!>x<!><!UNSAFE_CALL!>.<!>equals(10)
+        <!DEBUG_INFO_EXPRESSION_TYPE("T? & kotlin.Nothing? & K")!>x<!>
         println(1)
     }
 }
@@ -40,8 +40,8 @@ inline fun <reified T, reified K> case_3() {
 // TESTCASE NUMBER: 4
 inline fun <reified T, reified K> case_4(x: T?) {
     if (x is K) {
-        <!DEBUG_INFO_EXPRESSION_TYPE("T? & K!! & T?!!")!>x<!>
-        <!DEBUG_INFO_EXPRESSION_TYPE("T? & K!! & T?!!")!>x<!>.equals(x)
+        <!DEBUG_INFO_EXPRESSION_TYPE("T? & K & T?")!>x<!>
+        <!DEBUG_INFO_EXPRESSION_TYPE("T? & K & T?")!>x<!><!UNSAFE_CALL!>.<!>equals(x)
     }
 }
 
diff --git a/compiler/tests-spec/testData/diagnostics/notLinked/dfa/neg/41.fir.kt b/compiler/tests-spec/testData/diagnostics/notLinked/dfa/neg/41.fir.kt
index 838fdb7b345..930c7cabe0e 100644
--- a/compiler/tests-spec/testData/diagnostics/notLinked/dfa/neg/41.fir.kt
+++ b/compiler/tests-spec/testData/diagnostics/notLinked/dfa/neg/41.fir.kt
@@ -6,13 +6,13 @@
 inline fun <reified T> case_1(x: Any?) {
     when (x) {
         is T -> {
-            <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any? & T!!")!>x<!>
-            <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any? & T!!")!>x<!>.equals(10)
+            <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any? & T")!>x<!>
+            <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any? & T")!>x<!><!UNSAFE_CALL!>.<!>equals(10)
         }
         else -> return
     }
-    <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any? & T!!")!>x<!>
-    <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any? & T!!")!>x<!>.equals(10)
+    <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any? & T")!>x<!>
+    <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any? & T")!>x<!><!UNSAFE_CALL!>.<!>equals(10)
 }
 
 // TESTCASE NUMBER: 2
@@ -23,13 +23,13 @@ inline fun <reified T> case_2(x: Any?) {
             <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any? & kotlin.Any")!>x<!>.equals(10)
         }
         is T -> {
-            <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any? & T!!")!>x<!>
-            <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any? & T!!")!>x<!>.equals(10)
+            <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any? & T")!>x<!>
+            <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any? & T")!>x<!><!UNSAFE_CALL!>.<!>equals(10)
         }
         else -> return
     }
-    <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any? & kotlin.Any")!>x<!>
-    <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any? & kotlin.Any")!>x<!>.equals(10)
+    <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any?")!>x<!>
+    <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any?")!>x<!><!UNSAFE_CALL!>.<!>equals(10)
 }
 
 // TESTCASE NUMBER: 3
@@ -61,11 +61,11 @@ inline fun <reified T> case_4(x: Any?) {
 // TESTCASE NUMBER: 5
 inline fun <reified T> case_5(x: Any?) {
     if (x is T) {
-        <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any? & T!!")!>x<!>
-        <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any? & T!!")!>x<!>.equals(10)
+        <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any? & T")!>x<!>
+        <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any? & T")!>x<!><!UNSAFE_CALL!>.<!>equals(10)
     } else return
-    <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any? & T!!")!>x<!>
-    <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any? & T!!")!>x<!>.equals(10)
+    <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any? & T")!>x<!>
+    <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any? & T")!>x<!><!UNSAFE_CALL!>.<!>equals(10)
 }
 
 // TESTCASE NUMBER: 6
@@ -81,9 +81,9 @@ inline fun <reified T> case_7(x: Any?) {
         <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any? & kotlin.Any")!>x<!>
         <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any? & kotlin.Any")!>x<!>.equals(10)
     } else if (x is T) {
-        <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any? & T!!")!>x<!>
-        <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any? & T!!")!>x<!>.equals(10)
+        <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any? & T")!>x<!>
+        <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any? & T")!>x<!><!UNSAFE_CALL!>.<!>equals(10)
     } else return
-    <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any? & kotlin.Any")!>x<!>
-    <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any? & kotlin.Any")!>x<!>.equals(10)
+    <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any?")!>x<!>
+    <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any?")!>x<!><!UNSAFE_CALL!>.<!>equals(10)
 }
diff --git a/compiler/tests-spec/testData/diagnostics/notLinked/dfa/pos/22.fir.kt b/compiler/tests-spec/testData/diagnostics/notLinked/dfa/pos/22.fir.kt
index 1ebedfb4d7c..55bad8b0f55 100644
--- a/compiler/tests-spec/testData/diagnostics/notLinked/dfa/pos/22.fir.kt
+++ b/compiler/tests-spec/testData/diagnostics/notLinked/dfa/pos/22.fir.kt
@@ -118,7 +118,7 @@ fun case_11(x: Any?) {
 inline fun <reified T, reified K>case_12(x: Any?) {
     if (x is T) {
         if (<!USELESS_IS_CHECK!>x is T<!> is K) {
-            <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any? & T!!")!>x<!>
+            <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any? & T")!>x<!>
         }
     }
 }
@@ -127,7 +127,7 @@ inline fun <reified T, reified K>case_12(x: Any?) {
 inline fun <reified T, reified K>case_13(x: Any?) {
     if (x is T) {
         if (x is K) {
-            <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any? & T!! & K!!")!>x<!>
+            <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any? & T & K")!>x<!>
         }
     }
 }
@@ -136,7 +136,7 @@ inline fun <reified T, reified K>case_13(x: Any?) {
 inline fun <reified T, reified K>case_14(x: Any?) {
     if (x is T) {
         if (<!USELESS_IS_CHECK!>x !is T<!>) {
-            <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any? & T!!")!>x<!>
+            <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any? & T")!>x<!>
         }
     }
 }
@@ -145,7 +145,7 @@ inline fun <reified T, reified K>case_14(x: Any?) {
 inline fun <reified T, reified K>case_15(x: Any?) {
     if (x !is T) {
         if (x is T) {
-            <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any? & T!!")!>x<!>
+            <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any? & T")!>x<!>
         }
     }
 }