diff --git a/analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/DiagnosticCompilerTestFE10TestdataTestGenerated.java b/analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/DiagnosticCompilerTestFE10TestdataTestGenerated.java
index c998b088c93..87ac4fa0f75 100644
--- a/analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/DiagnosticCompilerTestFE10TestdataTestGenerated.java
+++ b/analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/DiagnosticCompilerTestFE10TestdataTestGenerated.java
@@ -8829,6 +8829,12 @@ public class DiagnosticCompilerTestFE10TestdataTestGenerated extends AbstractDia
                     runTest("compiler/testData/diagnostics/tests/delegatedProperty/inference/callableReferenceArgumentInDelegatedExpression.kt");
                 }
 
+                @Test
+                @TestMetadata("decoratedLambda.kt")
+                public void testDecoratedLambda() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/delegatedProperty/inference/decoratedLambda.kt");
+                }
+
                 @Test
                 @TestMetadata("delegateExpressionAsLambda.kt")
                 public void testDelegateExpressionAsLambda() throws Exception {
diff --git a/analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/LLFirPreresolvedReversedDiagnosticCompilerFE10TestDataTestGenerated.java b/analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/LLFirPreresolvedReversedDiagnosticCompilerFE10TestDataTestGenerated.java
index c88e3125643..47ae74e9aff 100644
--- a/analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/LLFirPreresolvedReversedDiagnosticCompilerFE10TestDataTestGenerated.java
+++ b/analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/LLFirPreresolvedReversedDiagnosticCompilerFE10TestDataTestGenerated.java
@@ -8829,6 +8829,12 @@ public class LLFirPreresolvedReversedDiagnosticCompilerFE10TestDataTestGenerated
                     runTest("compiler/testData/diagnostics/tests/delegatedProperty/inference/callableReferenceArgumentInDelegatedExpression.kt");
                 }
 
+                @Test
+                @TestMetadata("decoratedLambda.kt")
+                public void testDecoratedLambda() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/delegatedProperty/inference/decoratedLambda.kt");
+                }
+
                 @Test
                 @TestMetadata("delegateExpressionAsLambda.kt")
                 public void testDelegateExpressionAsLambda() throws Exception {
diff --git a/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirLightTreeOldFrontendDiagnosticsTestGenerated.java b/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirLightTreeOldFrontendDiagnosticsTestGenerated.java
index ec59ea89476..25ca8ed4da5 100644
--- a/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirLightTreeOldFrontendDiagnosticsTestGenerated.java
+++ b/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirLightTreeOldFrontendDiagnosticsTestGenerated.java
@@ -8829,6 +8829,12 @@ public class FirLightTreeOldFrontendDiagnosticsTestGenerated extends AbstractFir
                     runTest("compiler/testData/diagnostics/tests/delegatedProperty/inference/callableReferenceArgumentInDelegatedExpression.kt");
                 }
 
+                @Test
+                @TestMetadata("decoratedLambda.kt")
+                public void testDecoratedLambda() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/delegatedProperty/inference/decoratedLambda.kt");
+                }
+
                 @Test
                 @TestMetadata("delegateExpressionAsLambda.kt")
                 public void testDelegateExpressionAsLambda() throws Exception {
diff --git a/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirPsiOldFrontendDiagnosticsTestGenerated.java b/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirPsiOldFrontendDiagnosticsTestGenerated.java
index 5f62ff7cb91..9ab54e0771a 100644
--- a/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirPsiOldFrontendDiagnosticsTestGenerated.java
+++ b/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirPsiOldFrontendDiagnosticsTestGenerated.java
@@ -8835,6 +8835,12 @@ public class FirPsiOldFrontendDiagnosticsTestGenerated extends AbstractFirPsiDia
                     runTest("compiler/testData/diagnostics/tests/delegatedProperty/inference/callableReferenceArgumentInDelegatedExpression.kt");
                 }
 
+                @Test
+                @TestMetadata("decoratedLambda.kt")
+                public void testDecoratedLambda() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/delegatedProperty/inference/decoratedLambda.kt");
+                }
+
                 @Test
                 @TestMetadata("delegateExpressionAsLambda.kt")
                 public void testDelegateExpressionAsLambda() throws Exception {
diff --git a/compiler/fir/providers/src/org/jetbrains/kotlin/fir/resolve/LookupTagUtils.kt b/compiler/fir/providers/src/org/jetbrains/kotlin/fir/resolve/LookupTagUtils.kt
index 39e65f1d828..cf3d4e3fad0 100644
--- a/compiler/fir/providers/src/org/jetbrains/kotlin/fir/resolve/LookupTagUtils.kt
+++ b/compiler/fir/providers/src/org/jetbrains/kotlin/fir/resolve/LookupTagUtils.kt
@@ -31,6 +31,7 @@ fun ConeClassifierLookupTag.toSymbol(useSiteSession: FirSession): FirClassifierS
     when (this) {
         is ConeClassLikeLookupTag -> toSymbol(useSiteSession)
         is ConeClassifierLookupTagWithFixedSymbol -> this.symbol
+        // TODO: replace null with error(), see KT-57921
         else -> null
     }
 
@@ -136,4 +137,3 @@ private fun Collection<ConeKotlinType>.findClassRepresentationThatIsSubtypeOf(
     supertype: ConeKotlinType,
     session: FirSession
 ): ConeClassLikeLookupTag? = firstOrNull { it.isSubtypeOf(supertype, session) }?.findClassRepresentation(supertype, session)
-
diff --git a/compiler/fir/providers/src/org/jetbrains/kotlin/fir/types/ConeTypeContext.kt b/compiler/fir/providers/src/org/jetbrains/kotlin/fir/types/ConeTypeContext.kt
index 53685eb1521..e8b238eabc5 100644
--- a/compiler/fir/providers/src/org/jetbrains/kotlin/fir/types/ConeTypeContext.kt
+++ b/compiler/fir/providers/src/org/jetbrains/kotlin/fir/types/ConeTypeContext.kt
@@ -480,13 +480,12 @@ interface ConeTypeContext : TypeSystemContext, TypeSystemOptimizationContext, Ty
         return when (this) {
             is ConeFlexibleType -> this.upperBound.isNullableType()
             is ConeTypeParameterType -> lookupTag.symbol.allBoundsAreNullableOrUnresolved()
-            is ConeTypeVariableType -> {
-                val symbol = lookupTag.toSymbol(session) ?: return false
-                when (symbol) {
-                    is FirClassSymbol -> false
-                    is FirTypeAliasSymbol -> symbol.fir.expandedConeType?.isNullableType() ?: false
-                    is FirTypeParameterSymbol -> symbol.allBoundsAreNullableOrUnresolved()
-                }
+            // NB: There's no branch for ConeTypeVariableType, i.e. it always returns false for them
+            // And while it seems reasonable to have similar semantics as for stub types, it would make some diagnostic test failing
+            // Thus, we leave the same semantics only for stubs (similar to TypeUtils.isNullableType)
+            is ConeStubType -> {
+                val symbol = (this.constructor.variable.defaultType.lookupTag.originalTypeParameter as? ConeTypeParameterLookupTag)?.symbol
+                symbol == null || symbol.allBoundsAreNullableOrUnresolved()
             }
             is ConeIntersectionType -> intersectedTypes.all { it.isNullableType() }
             is ConeClassLikeType -> directExpansionType(session)?.isNullableType() ?: false
diff --git a/compiler/testData/diagnostics/tests/delegatedProperty/inference/decoratedLambda.kt b/compiler/testData/diagnostics/tests/delegatedProperty/inference/decoratedLambda.kt
new file mode 100644
index 00000000000..bfd88e7cfcd
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/delegatedProperty/inference/decoratedLambda.kt
@@ -0,0 +1,21 @@
+// FIR_IDENTICAL
+// ISSUE: KT-57814
+import kotlin.reflect.KProperty
+
+fun <P2> xComponent(
+    builder: (prop1: P2) -> Unit
+): (prop1: P2) -> Unit = {}
+
+operator fun <P1> ((prop1: P1) -> Unit).getValue(
+    thisRef: Any?,
+    property: KProperty<*>
+): (prop1: P1) -> Unit = this
+
+val pdfDocumentViewer by xComponent { _: String? ->
+}
+
+fun xPDFDocumentViewer(
+    href: String?
+) = pdfDocumentViewer(
+    href // Should be OK to pass nullable String? there
+)
diff --git a/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/DiagnosticTestGenerated.java b/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/DiagnosticTestGenerated.java
index 8443c0c25c3..4b2f2c42daa 100644
--- a/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/DiagnosticTestGenerated.java
+++ b/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/DiagnosticTestGenerated.java
@@ -8835,6 +8835,12 @@ public class DiagnosticTestGenerated extends AbstractDiagnosticTest {
                     runTest("compiler/testData/diagnostics/tests/delegatedProperty/inference/callableReferenceArgumentInDelegatedExpression.kt");
                 }
 
+                @Test
+                @TestMetadata("decoratedLambda.kt")
+                public void testDecoratedLambda() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/delegatedProperty/inference/decoratedLambda.kt");
+                }
+
                 @Test
                 @TestMetadata("delegateExpressionAsLambda.kt")
                 public void testDelegateExpressionAsLambda() throws Exception {