diff --git a/compiler/fir/resolve/tests/org/jetbrains/kotlin/fir/FirDiagnosticsSmokeTestGenerated.java b/compiler/fir/resolve/tests/org/jetbrains/kotlin/fir/FirDiagnosticsSmokeTestGenerated.java
index 114ba25642f..4a00ec72b01 100644
--- a/compiler/fir/resolve/tests/org/jetbrains/kotlin/fir/FirDiagnosticsSmokeTestGenerated.java
+++ b/compiler/fir/resolve/tests/org/jetbrains/kotlin/fir/FirDiagnosticsSmokeTestGenerated.java
@@ -10434,6 +10434,11 @@ public class FirDiagnosticsSmokeTestGenerated extends AbstractFirDiagnosticsSmok
                 runTest("compiler/testData/diagnostics/tests/inference/constraints/recursiveJavaTypeWithStarProjection.kt");
             }
 
+            @TestMetadata("remainConstraintContainingTypeWithoutProjection.kt")
+            public void testRemainConstraintContainingTypeWithoutProjection() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/inference/constraints/remainConstraintContainingTypeWithoutProjection.kt");
+            }
+
             @TestMetadata("returnLambdaFromLambda.kt")
             public void testReturnLambdaFromLambda() throws Exception {
                 runTest("compiler/testData/diagnostics/tests/inference/constraints/returnLambdaFromLambda.kt");
diff --git a/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/inference/components/ConstraintIncorporator.kt b/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/inference/components/ConstraintIncorporator.kt
index 09a04d2a59c..19134a565d2 100644
--- a/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/inference/components/ConstraintIncorporator.kt
+++ b/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/inference/components/ConstraintIncorporator.kt
@@ -157,7 +157,6 @@ class ConstraintIncorporator(
         isSubtype: Boolean
     ) {
         if (targetVariable in getNestedTypeVariables(newConstraint)) return
-        if (!containsConstrainingTypeWithoutProjection(newConstraint, otherConstraint)) return
         if (trivialConstraintTypeInferenceOracle.isGeneratedConstraintTrivial(
                 baseConstraint, otherConstraint, newConstraint, isSubtype
             )
@@ -173,15 +172,6 @@ class ConstraintIncorporator(
         addNewIncorporatedConstraint(targetVariable, newConstraint, ConstraintContext(kind, derivedFrom))
     }
 
-    fun Context.containsConstrainingTypeWithoutProjection(
-        newConstraint: KotlinTypeMarker,
-        otherConstraint: Constraint
-    ): Boolean {
-        return getNestedArguments(newConstraint).any {
-            it.getType().typeConstructor() == otherConstraint.type.typeConstructor() && it.getVariance() == TypeVariance.INV
-        }
-    }
-
     fun Context.getNestedTypeVariables(type: KotlinTypeMarker): List<TypeVariableMarker> =
         getNestedArguments(type).mapNotNull { getTypeVariable(it.getType().typeConstructor()) }
 
diff --git a/compiler/testData/diagnostics/tests/inference/commonSystem/postponedCompletionWithExactAnnotation_ni.kt b/compiler/testData/diagnostics/tests/inference/commonSystem/postponedCompletionWithExactAnnotation_ni.kt
index 2c3d7222ac0..4f68473d864 100644
--- a/compiler/testData/diagnostics/tests/inference/commonSystem/postponedCompletionWithExactAnnotation_ni.kt
+++ b/compiler/testData/diagnostics/tests/inference/commonSystem/postponedCompletionWithExactAnnotation_ni.kt
@@ -1,5 +1,5 @@
 // !LANGUAGE: +NewInference
-// !DIAGNOSTICS: -UNUSED_PARAMETER
+// !DIAGNOSTICS: -UNUSED_PARAMETER -UNUSED_VARIABLE -UNCHECKED_CAST
 
 interface ISample
 
@@ -9,15 +9,16 @@ fun <K> elvisSimple(x: K?, y: K): K = y
 fun <K> elvisExact(x: K?, y: K): @kotlin.internal.Exact K = y
 
 fun <T : Number> materialize(): T? = null
+fun <T> Any?.materialize(): T = null as T
 
 fun test(nullableSample: ISample, any: Any) {
-    <!DEBUG_INFO_EXPRESSION_TYPE("ISample")!><!TYPE_MISMATCH!>elvisSimple<!>(
+    <!DEBUG_INFO_EXPRESSION_TYPE("ISample?")!>elvisSimple(
         nullableSample,
         <!DEBUG_INFO_EXPRESSION_TYPE("{ISample & Number}?")!>materialize()<!>
     )<!>
 
     elvisSimple(
-        <!DEBUG_INFO_EXPRESSION_TYPE("ISample")!><!TYPE_MISMATCH!>elvisSimple<!>(nullableSample, materialize())<!>,
+        <!DEBUG_INFO_EXPRESSION_TYPE("ISample?")!>elvisSimple(nullableSample, materialize())<!>,
         any
     )
 
@@ -25,4 +26,14 @@ fun test(nullableSample: ISample, any: Any) {
         <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Any?")!>elvisExact(nullableSample, materialize())<!>,
         any
     )
+
+    val a: String? = null
+
+    val x1: String? = run {
+        a ?: <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.String?")!>a?.materialize()<!>
+    }
+
+    val x2 = run {
+        a ?: <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.String?")!>a?.materialize()<!>
+    }
 }
diff --git a/compiler/testData/diagnostics/tests/inference/commonSystem/postponedCompletionWithExactAnnotation_ni.txt b/compiler/testData/diagnostics/tests/inference/commonSystem/postponedCompletionWithExactAnnotation_ni.txt
index 84135a36988..8198e4ac6b2 100644
--- a/compiler/testData/diagnostics/tests/inference/commonSystem/postponedCompletionWithExactAnnotation_ni.txt
+++ b/compiler/testData/diagnostics/tests/inference/commonSystem/postponedCompletionWithExactAnnotation_ni.txt
@@ -4,6 +4,7 @@ package
 public fun </*0*/ K> elvisSimple(/*0*/ x: K?, /*1*/ y: K): K
 public fun </*0*/ T : kotlin.Number> materialize(): T?
 public fun test(/*0*/ nullableSample: ISample, /*1*/ any: kotlin.Any): kotlin.Unit
+public fun </*0*/ T> kotlin.Any?.materialize(): T
 
 public interface ISample {
     public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
diff --git a/compiler/testData/diagnostics/tests/inference/constraints/errorUpperBoundConstraint.kt b/compiler/testData/diagnostics/tests/inference/constraints/errorUpperBoundConstraint.kt
index 187422bdd1c..26de6fec138 100644
--- a/compiler/testData/diagnostics/tests/inference/constraints/errorUpperBoundConstraint.kt
+++ b/compiler/testData/diagnostics/tests/inference/constraints/errorUpperBoundConstraint.kt
@@ -20,7 +20,7 @@ public class Foo {
 // FILE: test.kt
 
 fun test(e: <!UNRESOLVED_REFERENCE!>ErrorType<!>) {
-    Foo.<!NEW_INFERENCE_NO_INFORMATION_FOR_PARAMETER!>foo<!> {
+    Foo.foo {
         Sam.Result.create(<!DEBUG_INFO_ELEMENT_WITH_ERROR_TYPE!>e<!>)
     }
 }
\ No newline at end of file
diff --git a/compiler/testData/diagnostics/tests/inference/constraints/remainConstraintContainingTypeWithoutProjection.kt b/compiler/testData/diagnostics/tests/inference/constraints/remainConstraintContainingTypeWithoutProjection.kt
new file mode 100644
index 00000000000..c3add8bad9e
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/inference/constraints/remainConstraintContainingTypeWithoutProjection.kt
@@ -0,0 +1,30 @@
+// !LANGUAGE: +NewInference
+// !DIAGNOSTICS: -UNUSED_PARAMETER -CAST_NEVER_SUCCEEDS
+// SKIP_TXT
+
+// FILE: Test.java
+import java.util.Collection;
+
+public class Test {
+    static <T> Inv<Collection<? extends T>> bar() {
+        return null;
+    }
+}
+
+// FILE: main.kt
+class Inv<E>
+
+fun <R> foo(x: R, y: Inv<R>) {}
+
+fun main() {
+    val values: List<Int> = null as List<Int>
+    /*
+     * Before the fix, there was type mismatch during checking `Test.bar()` to pass to `foo`:
+     *      Required: Inv<List<Int>>
+     *      Found: Inv<(MutableCollection<out Int!>..Collection<Int!>?)>
+     * Constraint `(MutableCollection<out T!>..Collection<T!>?)` from 'Found' (for TypeVariable(R)) has been removed
+     * during fixation TypeVariable(T) due to the constraint for R contained TypeVariable(T).
+     * The problem was that TypeVariable(T) wan't substituted due to `containsConstrainingTypeWithoutProjection` optimization.
+     */
+    foo(values, Test.bar())
+}
\ No newline at end of file
diff --git a/compiler/tests/org/jetbrains/kotlin/checkers/DiagnosticsTestGenerated.java b/compiler/tests/org/jetbrains/kotlin/checkers/DiagnosticsTestGenerated.java
index 0b0ccd56f03..2091357c9b6 100644
--- a/compiler/tests/org/jetbrains/kotlin/checkers/DiagnosticsTestGenerated.java
+++ b/compiler/tests/org/jetbrains/kotlin/checkers/DiagnosticsTestGenerated.java
@@ -10441,6 +10441,11 @@ public class DiagnosticsTestGenerated extends AbstractDiagnosticsTest {
                     runTest("compiler/testData/diagnostics/tests/inference/constraints/recursiveJavaTypeWithStarProjection.kt");
                 }
 
+                @TestMetadata("remainConstraintContainingTypeWithoutProjection.kt")
+                public void testRemainConstraintContainingTypeWithoutProjection() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/inference/constraints/remainConstraintContainingTypeWithoutProjection.kt");
+                }
+
                 @TestMetadata("returnLambdaFromLambda.kt")
                 public void testReturnLambdaFromLambda() throws Exception {
                     runTest("compiler/testData/diagnostics/tests/inference/constraints/returnLambdaFromLambda.kt");
diff --git a/compiler/tests/org/jetbrains/kotlin/checkers/javac/DiagnosticsUsingJavacTestGenerated.java b/compiler/tests/org/jetbrains/kotlin/checkers/javac/DiagnosticsUsingJavacTestGenerated.java
index 77ebe60bf73..435510097fb 100644
--- a/compiler/tests/org/jetbrains/kotlin/checkers/javac/DiagnosticsUsingJavacTestGenerated.java
+++ b/compiler/tests/org/jetbrains/kotlin/checkers/javac/DiagnosticsUsingJavacTestGenerated.java
@@ -10436,6 +10436,11 @@ public class DiagnosticsUsingJavacTestGenerated extends AbstractDiagnosticsUsing
                     runTest("compiler/testData/diagnostics/tests/inference/constraints/recursiveJavaTypeWithStarProjection.kt");
                 }
 
+                @TestMetadata("remainConstraintContainingTypeWithoutProjection.kt")
+                public void testRemainConstraintContainingTypeWithoutProjection() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/inference/constraints/remainConstraintContainingTypeWithoutProjection.kt");
+                }
+
                 @TestMetadata("returnLambdaFromLambda.kt")
                 public void testReturnLambdaFromLambda() throws Exception {
                     runTest("compiler/testData/diagnostics/tests/inference/constraints/returnLambdaFromLambda.kt");