diff --git a/compiler/tests-spec/testData/diagnostics/linked/type-inference/smart-casts/smart-cast-sink-stability/p-5/neg/1.1.fir.kt b/compiler/tests-spec/testData/diagnostics/linked/type-inference/smart-casts/smart-cast-sink-stability/p-5/neg/1.1.fir.kt
new file mode 100644
index 00000000000..d99c80f3ce9
--- /dev/null
+++ b/compiler/tests-spec/testData/diagnostics/linked/type-inference/smart-casts/smart-cast-sink-stability/p-5/neg/1.1.fir.kt
@@ -0,0 +1,43 @@
+// !LANGUAGE: +NewInference
+// !DIAGNOSTICS: -UNUSED_VARIABLE -ASSIGNED_BUT_NEVER_ACCESSED_VARIABLE -UNUSED_VALUE -UNUSED_PARAMETER -UNUSED_EXPRESSION
+// SKIP_TXT
+
+/*
+ * KOTLIN DIAGNOSTICS SPEC TEST (NEGATIVE)
+ *
+ * SPEC VERSION: 0.1-268
+ * PLACE:  type-inference, smart-casts, smart-cast-sink-stability -> paragraph 5 -> sentence 1
+ * RELEVANT PLACES: overload-resolution, building-the-overload-candidate-set-ocs, operator-call -> paragraph 4 -> sentence 1
+ * overload-resolution, building-the-overload-candidate-set-ocs, operator-call -> paragraph 2 -> sentence 1
+ * NUMBER: 1
+ * DESCRIPTION: smart case for property `plus` available through the operator invoke
+ * UNEXPECTED BEHAVIOUR
+ * ISSUES: KT-36876
+ */
+// TESTCASE NUMBER: 1
+class Case1() {
+
+    class E(val plus: Inv? = null, val value: Inv? = null)
+
+    class Inv() {
+        operator fun invoke(value: Int) = Case1()
+    }
+
+    fun foo(e: E) {
+
+        if (e.plus != null) {
+            run { e + 1 }
+
+            /*
+             [PROPERTY_AS_OPERATOR]  (ok)
+             Properties cannot be used in operator conventions: 'invoke' in 'operatorCall.Case1.Inv'
+             [UNSAFE_OPERATOR_CALL]  (nok)
+             Operator call corresponds to a dot-qualified call 'e.plus(1)' which is not allowed on a nullable receiver 'e'.
+            */
+            e + 1
+
+            e.plus.invoke(1) //ok
+        }
+
+    }
+}
diff --git a/compiler/tests-spec/testData/diagnostics/linked/type-inference/smart-casts/smart-cast-sink-stability/p-5/pos/1.1.fir.kt b/compiler/tests-spec/testData/diagnostics/linked/type-inference/smart-casts/smart-cast-sink-stability/p-5/pos/1.1.fir.kt
new file mode 100644
index 00000000000..84e69888912
--- /dev/null
+++ b/compiler/tests-spec/testData/diagnostics/linked/type-inference/smart-casts/smart-cast-sink-stability/p-5/pos/1.1.fir.kt
@@ -0,0 +1,38 @@
+// !LANGUAGE: +NewInference
+// !DIAGNOSTICS: -UNUSED_VARIABLE -ASSIGNED_BUT_NEVER_ACCESSED_VARIABLE -UNUSED_VALUE -UNUSED_PARAMETER -UNUSED_EXPRESSION
+// SKIP_TXT
+
+/*
+ * KOTLIN DIAGNOSTICS SPEC TEST (POSITIVE)
+ *
+ * SPEC VERSION: 0.1-268
+ * PLACE: type-inference, smart-casts, smart-cast-sink-stability -> paragraph 5 -> sentence 1
+ * RELEVANT PLACES: overload-resolution, building-the-overload-candidate-set-ocs, call-with-an-explicit-receiver -> paragraph 1 -> sentence 1
+ * overload-resolution, building-the-overload-candidate-set-ocs, call-with-an-explicit-receiver -> paragraph 3 -> sentence 1
+ * NUMBER: 1
+ * DESCRIPTION: smart cast for the property available through the operator invoke
+ * UNEXPECTED BEHAVIOUR
+ * ISSUES: KT-36876
+ */
+// TESTCASE NUMBER: 1
+class Case1() {
+
+    class E(val plus: Inv? = null, val value: Inv? = null)
+
+    class Inv() {
+        operator fun invoke(value: Int) = Case1()
+    }
+
+    fun foo(e: E) {
+
+        if (e.value != null) {
+            run { e.value(1) }
+            /*
+             [UNSAFE_CALL] (nok)
+             Only safe (?.) or non-null asserted (!!.) calls are allowed on a nullable receiver of type Case1.Inv?
+            */
+            e.value(1)
+
+        }
+    }
+}
diff --git a/compiler/tests-spec/testData/diagnostics/notLinked/local-variables/type-parameters/neg/1.fir.kt b/compiler/tests-spec/testData/diagnostics/notLinked/local-variables/type-parameters/neg/1.fir.kt
new file mode 100644
index 00000000000..fa0a164f4a2
--- /dev/null
+++ b/compiler/tests-spec/testData/diagnostics/notLinked/local-variables/type-parameters/neg/1.fir.kt
@@ -0,0 +1,104 @@
+// !DIAGNOSTICS: -UNUSED_VARIABLE
+// SKIP_TXT
+
+/*
+ * KOTLIN DIAGNOSTICS NOT LINKED SPEC TEST (NEGATIVE)
+ *
+ * SECTIONS: local-variables, type-parameters
+ * NUMBER: 1
+ * DESCRIPTION: Local variables with forbidden type parameters.
+ * UNEXPECTED BEHAVIOUR
+ * ISSUES: KT-8341
+ */
+
+// TESTCASE NUMBER: 1
+fun case_1() {
+    val <T> x1 = 1
+    var <T> x2 = 1
+}
+
+// TESTCASE NUMBER: 2
+fun case_2() {
+    val <T> x1: Int = 1
+    var <T> x2: Int = 1
+}
+
+// TESTCASE NUMBER: 3
+fun case_3() {
+    val <T> x1: Map<Int, Int> = mapOf(1 to 1)
+    var <T> x2: Map<Int, Int> = mapOf(1 to 1)
+}
+
+// TESTCASE NUMBER: 4
+fun case_4() {
+    val <T> y1: Number where __UNRESOLVED__: __UNRESOLVED__ = 1
+    var <T> y2: Number where __UNRESOLVED__: __UNRESOLVED__ = 1
+}
+
+// TESTCASE NUMBER: 5
+fun case_5() {
+    val <T : __UNRESOLVED__> x1: Map<Int, Int> = mapOf(1 to 1)
+    var <T : __UNRESOLVED__> x2: Map<Int, Int> = mapOf(1 to 1)
+}
+
+/*
+ * TESTCASE NUMBER: 6
+ * UNEXPECTED BEHAVIOUR
+ */
+fun case_6() {
+    val <T : __UNRESOLVED__> (x1, y1) = Pair(1, 2)
+    var <T : __UNRESOLVED__> (x2, y2) = Pair(1, 2)
+}
+
+/*
+ * TESTCASE NUMBER: 7
+ * UNEXPECTED BEHAVIOUR
+ */
+fun case_7() {
+    val <T : __UNRESOLVED__> (x1, y1) where __UNRESOLVED__: __UNRESOLVED__ = Pair(1, 2)
+    var <T : __UNRESOLVED__> (x2, y2) where __UNRESOLVED__: __UNRESOLVED__ = Pair(1, 2)
+}
+
+// TESTCASE NUMBER: 8
+fun case_8() {
+    val <A, B : A, C : B, D : C, E : D> x1 = 1
+    var <A, B : A, C : B, D : C, E : D> x2 = 2
+}
+
+// TESTCASE NUMBER: 9
+fun case_9(y: Boolean?) = when (val <T> x = y) {
+    true -> null
+    false -> null
+    null -> null
+}
+
+// TESTCASE NUMBER: 10
+fun case_10(x: Boolean?) = when (val <T> x where T: suspend () -> Unit, T: Boolean = x) {
+    true -> null
+    false -> null
+    null -> null
+}
+
+// TESTCASE NUMBER: 11
+fun case_11() {
+    val <T> x by lazy { 1 }
+    var <T> x by lazy { 1 }
+}
+
+// TESTCASE NUMBER: 12
+fun case_12() {
+    val <T : __UNRESOLVED__> x: Int
+    var <T : __UNRESOLVED__> x: Int
+}
+
+// TESTCASE NUMBER: 13
+fun case_13() {
+    val <T : __UNRESOLVED__> x: Int where __UNRESOLVED__: __UNRESOLVED__
+    var <T : __UNRESOLVED__> x: Int where __UNRESOLVED__: __UNRESOLVED__
+}
+
+// TESTCASE NUMBER: 14
+fun case_14() {
+    val <T : T> x1 = 1
+    var <T : T> x2 = 1
+}