diff --git a/compiler/testData/codegen/box/builderInference/issues/kt52838a.kt b/compiler/testData/codegen/box/builderInference/issues/kt52838a.kt
new file mode 100644
index 00000000000..1d2c6ae116a
--- /dev/null
+++ b/compiler/testData/codegen/box/builderInference/issues/kt52838a.kt
@@ -0,0 +1,30 @@
+// ISSUE: KT-52838
+
+// IGNORE_LIGHT_ANALYSIS
+// IGNORE_BACKEND: ANY
+// REASON: red code (see corresponding diagnostic test)
+
+fun box(): String {
+    build {
+        this as DerivedBuildee<*, *>
+        getTypeVariableA()
+        getTypeVariableB()
+    }
+    return "OK"
+}
+
+
+
+
+open class Buildee<TVA, TVB> {
+    fun getTypeVariableA(): TVA = storageA
+    fun getTypeVariableB(): TVB = storageB
+    private var storageA: TVA = Any() as TVA
+    private var storageB: TVB = Any() as TVB
+}
+
+class DerivedBuildee<TAA, TAB>: Buildee<TAA, TAB>()
+
+fun <PTVA, PTVB> build(instructions: Buildee<PTVA, PTVB>.() -> Unit): Buildee<PTVA, PTVB> {
+    return DerivedBuildee<PTVA, PTVB>().apply(instructions)
+}
diff --git a/compiler/testData/codegen/box/builderInference/issues/kt52838b.kt b/compiler/testData/codegen/box/builderInference/issues/kt52838b.kt
new file mode 100644
index 00000000000..75f793a5945
--- /dev/null
+++ b/compiler/testData/codegen/box/builderInference/issues/kt52838b.kt
@@ -0,0 +1,28 @@
+// ISSUE: KT-52838
+
+// IGNORE_LIGHT_ANALYSIS
+// IGNORE_BACKEND: ANY
+// REASON: red code (see corresponding diagnostic test)
+
+fun box(): String {
+    build {
+        this as DerivedBuildee<*>
+        getTypeVariable()
+        getTypeVariable()
+    }
+    return "OK"
+}
+
+
+
+
+open class Buildee<TV> {
+    fun getTypeVariable(): TV = storage
+    private var storage: TV = Any() as TV
+}
+
+class DerivedBuildee<TA>: Buildee<TA>()
+
+fun <PTV> build(instructions: Buildee<PTV>.() -> Unit): Buildee<PTV> {
+    return DerivedBuildee<PTV>().apply(instructions)
+}
diff --git a/compiler/testData/codegen/box/builderInference/issues/kt52838c.kt b/compiler/testData/codegen/box/builderInference/issues/kt52838c.kt
new file mode 100644
index 00000000000..234db24b4f3
--- /dev/null
+++ b/compiler/testData/codegen/box/builderInference/issues/kt52838c.kt
@@ -0,0 +1,26 @@
+// ISSUE: KT-52838
+
+// IGNORE_BACKEND_K2: ANY
+// REASON: red code (see corresponding diagnostic test)
+
+fun box(): String {
+    build {
+        this as DerivedBuildee<*>
+        getTypeVariable()
+    }
+    return "OK"
+}
+
+
+
+
+open class Buildee<TV> {
+    fun getTypeVariable(): TV = storage
+    private var storage: TV = Any() as TV
+}
+
+class DerivedBuildee<TA>: Buildee<TA>()
+
+fun <PTV> build(instructions: Buildee<PTV>.() -> Unit): Buildee<PTV> {
+    return DerivedBuildee<PTV>().apply(instructions)
+}
diff --git a/compiler/testData/diagnostics/tests/builderInference/issues/kt52838a.fir.kt b/compiler/testData/diagnostics/tests/builderInference/issues/kt52838a.fir.kt
new file mode 100644
index 00000000000..aab51a0fc70
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/builderInference/issues/kt52838a.fir.kt
@@ -0,0 +1,29 @@
+// ISSUE: KT-52838
+// CHECK_TYPE_WITH_EXACT
+
+fun test() {
+    val buildee = <!NEW_INFERENCE_NO_INFORMATION_FOR_PARAMETER, NEW_INFERENCE_NO_INFORMATION_FOR_PARAMETER!>build<!> {
+        this as DerivedBuildee<*, *>
+        getTypeVariableA()
+        getTypeVariableB()
+    }
+    // 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
+    <!NEW_INFERENCE_NO_INFORMATION_FOR_PARAMETER!>checkExactType<!><<!CANNOT_INFER_PARAMETER_TYPE!>Buildee<*, *><!>>(buildee)
+}
+
+
+
+
+open class Buildee<TVA, TVB> {
+    fun getTypeVariableA(): TVA = storageA
+    fun getTypeVariableB(): TVB = storageB
+    private var storageA: TVA = null!!
+    private var storageB: TVB = null!!
+}
+
+class DerivedBuildee<TAA, TAB>: Buildee<TAA, TAB>()
+
+fun <PTVA, PTVB> build(instructions: Buildee<PTVA, PTVB>.() -> Unit): Buildee<PTVA, PTVB> {
+    return DerivedBuildee<PTVA, PTVB>().apply(instructions)
+}
diff --git a/compiler/testData/diagnostics/tests/builderInference/issues/kt52838a.kt b/compiler/testData/diagnostics/tests/builderInference/issues/kt52838a.kt
new file mode 100644
index 00000000000..6f48245ed3e
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/builderInference/issues/kt52838a.kt
@@ -0,0 +1,29 @@
+// ISSUE: KT-52838
+// CHECK_TYPE_WITH_EXACT
+
+fun test() {
+    val buildee = build {
+        this as DerivedBuildee<*, *>
+        getTypeVariableA()
+        <!RECEIVER_TYPE_MISMATCH("CapturedType(*); CapturedType(*)"), RECEIVER_TYPE_MISMATCH("CapturedType(*); CapturedType(*)"), RECEIVER_TYPE_MISMATCH("CapturedType(*); CapturedType(*)"), RECEIVER_TYPE_MISMATCH("CapturedType(*); CapturedType(*)")!>getTypeVariableB<!>()
+    }
+    // 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<*, *>>(<!TYPE_MISMATCH("Buildee<Any?, Any?>; Buildee<*, *>")!>buildee<!>)
+}
+
+
+
+
+open class Buildee<TVA, TVB> {
+    fun getTypeVariableA(): TVA = storageA
+    fun getTypeVariableB(): TVB = storageB
+    private var storageA: TVA = null!!
+    private var storageB: TVB = null!!
+}
+
+class DerivedBuildee<TAA, TAB>: Buildee<TAA, TAB>()
+
+fun <PTVA, PTVB> build(instructions: Buildee<PTVA, PTVB>.() -> Unit): Buildee<PTVA, PTVB> {
+    return DerivedBuildee<PTVA, PTVB>().apply(instructions)
+}
diff --git a/compiler/testData/diagnostics/tests/builderInference/issues/kt52838b.fir.kt b/compiler/testData/diagnostics/tests/builderInference/issues/kt52838b.fir.kt
new file mode 100644
index 00000000000..3be9a0a7e98
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/builderInference/issues/kt52838b.fir.kt
@@ -0,0 +1,27 @@
+// ISSUE: KT-52838
+// CHECK_TYPE_WITH_EXACT
+
+fun test() {
+    val buildee = <!NEW_INFERENCE_NO_INFORMATION_FOR_PARAMETER!>build<!> {
+        this as DerivedBuildee<*>
+        getTypeVariable()
+        getTypeVariable()
+    }
+    // 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
+    <!NEW_INFERENCE_NO_INFORMATION_FOR_PARAMETER!>checkExactType<!><<!CANNOT_INFER_PARAMETER_TYPE!>Buildee<*><!>>(buildee)
+}
+
+
+
+
+open class Buildee<TV> {
+    fun getTypeVariable(): TV = storage
+    private var storage: TV = null!!
+}
+
+class DerivedBuildee<TA>: Buildee<TA>()
+
+fun <PTV> build(instructions: Buildee<PTV>.() -> Unit): Buildee<PTV> {
+    return DerivedBuildee<PTV>().apply(instructions)
+}
diff --git a/compiler/testData/diagnostics/tests/builderInference/issues/kt52838b.kt b/compiler/testData/diagnostics/tests/builderInference/issues/kt52838b.kt
new file mode 100644
index 00000000000..3a4e75dc8f5
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/builderInference/issues/kt52838b.kt
@@ -0,0 +1,27 @@
+// ISSUE: KT-52838
+// CHECK_TYPE_WITH_EXACT
+
+fun test() {
+    val buildee = build {
+        this as DerivedBuildee<*>
+        getTypeVariable()
+        <!RECEIVER_TYPE_MISMATCH("CapturedType(*); CapturedType(*)"), RECEIVER_TYPE_MISMATCH("CapturedType(*); CapturedType(*)")!>getTypeVariable<!>()
+    }
+    // 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<*>>(<!TYPE_MISMATCH("Buildee<Any?>; Buildee<*>")!>buildee<!>)
+}
+
+
+
+
+open class Buildee<TV> {
+    fun getTypeVariable(): TV = storage
+    private var storage: TV = null!!
+}
+
+class DerivedBuildee<TA>: Buildee<TA>()
+
+fun <PTV> build(instructions: Buildee<PTV>.() -> Unit): Buildee<PTV> {
+    return DerivedBuildee<PTV>().apply(instructions)
+}
diff --git a/compiler/testData/diagnostics/tests/builderInference/issues/kt52838c.fir.kt b/compiler/testData/diagnostics/tests/builderInference/issues/kt52838c.fir.kt
new file mode 100644
index 00000000000..ce356f538f1
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/builderInference/issues/kt52838c.fir.kt
@@ -0,0 +1,26 @@
+// ISSUE: KT-52838
+// CHECK_TYPE_WITH_EXACT
+
+fun test() {
+    val buildee = <!NEW_INFERENCE_NO_INFORMATION_FOR_PARAMETER!>build<!> {
+        this as DerivedBuildee<*>
+        getTypeVariable()
+    }
+    // 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
+    <!NEW_INFERENCE_NO_INFORMATION_FOR_PARAMETER!>checkExactType<!><<!CANNOT_INFER_PARAMETER_TYPE!>Buildee<*><!>>(buildee)
+}
+
+
+
+
+open class Buildee<TV> {
+    fun getTypeVariable(): TV = storage
+    private var storage: TV = null!!
+}
+
+class DerivedBuildee<TA>: Buildee<TA>()
+
+fun <PTV> build(instructions: Buildee<PTV>.() -> Unit): Buildee<PTV> {
+    return DerivedBuildee<PTV>().apply(instructions)
+}
diff --git a/compiler/testData/diagnostics/tests/builderInference/issues/kt52838c.kt b/compiler/testData/diagnostics/tests/builderInference/issues/kt52838c.kt
new file mode 100644
index 00000000000..b2078ca3aaa
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/builderInference/issues/kt52838c.kt
@@ -0,0 +1,26 @@
+// ISSUE: KT-52838
+// CHECK_TYPE_WITH_EXACT
+
+fun test() {
+    val buildee = build {
+        this as DerivedBuildee<*>
+        getTypeVariable()
+    }
+    // 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<*>>(<!TYPE_MISMATCH("Buildee<Any?>; Buildee<*>")!>buildee<!>)
+}
+
+
+
+
+open class Buildee<TV> {
+    fun getTypeVariable(): TV = storage
+    private var storage: TV = null!!
+}
+
+class DerivedBuildee<TA>: Buildee<TA>()
+
+fun <PTV> build(instructions: Buildee<PTV>.() -> Unit): Buildee<PTV> {
+    return DerivedBuildee<PTV>().apply(instructions)
+}