diff --git a/compiler/testData/codegen/box/builderInference/issues/kt49263.kt b/compiler/testData/codegen/box/builderInference/issues/kt49263.kt
new file mode 100644
index 00000000000..6fe55aaa79f
--- /dev/null
+++ b/compiler/testData/codegen/box/builderInference/issues/kt49263.kt
@@ -0,0 +1,23 @@
+// ISSUE: KT-49263
+
+// IGNORE_LIGHT_ANALYSIS
+// IGNORE_BACKEND: ANY
+// REASON: red code (see corresponding diagnostic test)
+
+fun box(): String {
+    buildPostponedTypeVariable {
+        consumeTargetType(this)
+    }
+    return "OK"
+}
+
+
+
+
+class TargetType
+
+fun consumeTargetType(value: TargetType) {}
+
+fun <PTV> buildPostponedTypeVariable(block: PTV.() -> Unit): PTV {
+    return (TargetType() as PTV).apply(block)
+}
diff --git a/compiler/testData/diagnostics/tests/builderInference/issues/kt49263.fir.kt b/compiler/testData/diagnostics/tests/builderInference/issues/kt49263.fir.kt
new file mode 100644
index 00000000000..db8006a6d86
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/builderInference/issues/kt49263.fir.kt
@@ -0,0 +1,22 @@
+// ISSUE: KT-49263
+// CHECK_TYPE_WITH_EXACT
+
+fun test() {
+    val targetType = <!NEW_INFERENCE_NO_INFORMATION_FOR_PARAMETER!>buildPostponedTypeVariable<!> {
+        consumeTargetType(<!CANNOT_INFER_PARAMETER_TYPE!>this<!>)
+    }
+    // exact type equality check — turns unexpected compile-time behavior into red code
+    // considered to be non-user-reproducible code for the purposes of these tests
+    checkExactType<TargetType>(targetType)
+}
+
+
+
+
+class TargetType
+
+fun consumeTargetType(value: TargetType) {}
+
+fun <PTV> buildPostponedTypeVariable(block: PTV.() -> Unit): PTV {
+    return null!!
+}
diff --git a/compiler/testData/diagnostics/tests/builderInference/issues/kt49263.kt b/compiler/testData/diagnostics/tests/builderInference/issues/kt49263.kt
new file mode 100644
index 00000000000..471bd03bb2c
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/builderInference/issues/kt49263.kt
@@ -0,0 +1,22 @@
+// ISSUE: KT-49263
+// CHECK_TYPE_WITH_EXACT
+
+fun test() {
+    val targetType = <!NEW_INFERENCE_NO_INFORMATION_FOR_PARAMETER!>buildPostponedTypeVariable<!> {
+        <!DEBUG_INFO_MISSING_UNRESOLVED!>consumeTargetType<!>(this)
+    }
+    // exact type equality check — turns unexpected compile-time behavior into red code
+    // considered to be non-user-reproducible code for the purposes of these tests
+    checkExactType<TargetType>(<!DEBUG_INFO_ELEMENT_WITH_ERROR_TYPE!>targetType<!>)
+}
+
+
+
+
+class TargetType
+
+fun consumeTargetType(value: TargetType) {}
+
+fun <PTV> buildPostponedTypeVariable(block: PTV.() -> Unit): PTV {
+    return null!!
+}