diff --git a/compiler/testData/codegen/box/builderInference/issues/kt54767a.kt b/compiler/testData/codegen/box/builderInference/issues/kt54767a.kt
new file mode 100644
index 00000000000..849667cae40
--- /dev/null
+++ b/compiler/testData/codegen/box/builderInference/issues/kt54767a.kt
@@ -0,0 +1,26 @@
+// ISSUE: KT-54767
+// WITH_STDLIB
+
+fun box(): String {
+    val buildee by lazy {
+        build {
+            setTypeVariable(TargetType())
+        }
+    }
+    buildee
+    return "OK"
+}
+
+
+
+
+class TargetType
+
+class Buildee<TV> {
+    fun setTypeVariable(value: TV) { storage = value }
+    private var storage: TV = TargetType() as TV
+}
+
+fun <PTV> build(instructions: Buildee<PTV>.() -> Unit): Buildee<PTV> {
+    return Buildee<PTV>().apply(instructions)
+}
diff --git a/compiler/testData/codegen/box/builderInference/issues/kt54767b.kt b/compiler/testData/codegen/box/builderInference/issues/kt54767b.kt
new file mode 100644
index 00000000000..58c6c902516
--- /dev/null
+++ b/compiler/testData/codegen/box/builderInference/issues/kt54767b.kt
@@ -0,0 +1,29 @@
+// ISSUE: KT-54767
+// WITH_STDLIB
+
+class Klass {
+    val buildee by lazy {
+        build {
+            setTypeVariable(TargetType())
+        }
+    }
+}
+
+fun box(): String {
+    Klass().buildee
+    return "OK"
+}
+
+
+
+
+class TargetType
+
+class Buildee<TV> {
+    fun setTypeVariable(value: TV) { storage = value }
+    private var storage: TV = TargetType() as TV
+}
+
+fun <PTV> build(instructions: Buildee<PTV>.() -> Unit): Buildee<PTV> {
+    return Buildee<PTV>().apply(instructions)
+}
diff --git a/compiler/testData/diagnostics/tests/builderInference/issues/kt54767a.kt b/compiler/testData/diagnostics/tests/builderInference/issues/kt54767a.kt
new file mode 100644
index 00000000000..2cd63cf38dd
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/builderInference/issues/kt54767a.kt
@@ -0,0 +1,29 @@
+// ISSUE: KT-54767
+// FIR_IDENTICAL
+// CHECK_TYPE_WITH_EXACT
+// WITH_STDLIB
+
+fun test() {
+    val buildee by lazy {
+        build {
+            setTypeVariable(TargetType())
+        }
+    }
+    // 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<Buildee<TargetType>>(buildee)
+}
+
+
+
+
+class TargetType
+
+class Buildee<TV> {
+    fun setTypeVariable(value: TV) { storage = value }
+    private var storage: TV = null!!
+}
+
+fun <PTV> build(instructions: Buildee<PTV>.() -> Unit): Buildee<PTV> {
+    return Buildee<PTV>().apply(instructions)
+}
diff --git a/compiler/testData/diagnostics/tests/builderInference/issues/kt54767b.kt b/compiler/testData/diagnostics/tests/builderInference/issues/kt54767b.kt
new file mode 100644
index 00000000000..f1eb0f3a268
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/builderInference/issues/kt54767b.kt
@@ -0,0 +1,32 @@
+// ISSUE: KT-54767
+// FIR_IDENTICAL
+// CHECK_TYPE_WITH_EXACT
+// WITH_STDLIB
+
+class Klass {
+    val buildee by lazy {
+        build {
+            setTypeVariable(TargetType())
+        }
+    }
+}
+
+fun test() {
+    // 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<Buildee<TargetType>>(Klass().buildee)
+}
+
+
+
+
+class TargetType
+
+class Buildee<TV> {
+    fun setTypeVariable(value: TV) { storage = value }
+    private var storage: TV = null!!
+}
+
+fun <PTV> build(instructions: Buildee<PTV>.() -> Unit): Buildee<PTV> {
+    return Buildee<PTV>().apply(instructions)
+}