diff --git a/compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWith2Files/Baz.java b/compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWith2Files/Baz.java
new file mode 100644
index 00000000000..d5fd7bcb24a
--- /dev/null
+++ b/compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWith2Files/Baz.java
@@ -0,0 +1,5 @@
+public class Baz {
+    public static String baz() {
+        return Util.foo() + Util.bar();
+    }
+}
\ No newline at end of file
diff --git a/compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWith2Files/bar.kt b/compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWith2Files/bar.kt
new file mode 100644
index 00000000000..f5d29e0a6fc
--- /dev/null
+++ b/compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWith2Files/bar.kt
@@ -0,0 +1,3 @@
+@file:JvmName("Util")
+@file:JvmMultifileClass
+public fun bar(): String = "K"
\ No newline at end of file
diff --git a/compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWith2Files/foo.kt b/compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWith2Files/foo.kt
new file mode 100644
index 00000000000..74bb68ff299
--- /dev/null
+++ b/compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWith2Files/foo.kt
@@ -0,0 +1,3 @@
+@file:JvmName("Util")
+@file:JvmMultifileClass
+public fun foo(): String = "O"
\ No newline at end of file
diff --git a/compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWith2Files/multifileClassWith2Files.kt b/compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWith2Files/multifileClassWith2Files.kt
new file mode 100644
index 00000000000..936b887daa8
--- /dev/null
+++ b/compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWith2Files/multifileClassWith2Files.kt
@@ -0,0 +1 @@
+fun box(): String = Baz.baz()
\ No newline at end of file
diff --git a/compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWithInternal/Baz.java b/compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWithInternal/Baz.java
new file mode 100644
index 00000000000..d5fd7bcb24a
--- /dev/null
+++ b/compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWithInternal/Baz.java
@@ -0,0 +1,5 @@
+public class Baz {
+    public static String baz() {
+        return Util.foo() + Util.bar();
+    }
+}
\ No newline at end of file
diff --git a/compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWithInternal/bar.kt b/compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWithInternal/bar.kt
new file mode 100644
index 00000000000..120066c7e6b
--- /dev/null
+++ b/compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWithInternal/bar.kt
@@ -0,0 +1,5 @@
+@file:JvmName("Util")
+@file:JvmMultifileClass
+public fun bar(): String = barx()
+
+internal fun foox(): String = "O"
\ No newline at end of file
diff --git a/compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWithInternal/foo.kt b/compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWithInternal/foo.kt
new file mode 100644
index 00000000000..86c78c3ab08
--- /dev/null
+++ b/compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWithInternal/foo.kt
@@ -0,0 +1,5 @@
+@file:JvmName("Util")
+@file:JvmMultifileClass
+public fun foo(): String = foox()
+
+internal fun barx(): String = "K"
\ No newline at end of file
diff --git a/compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWithInternal/multifileClassWithInternal.kt b/compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWithInternal/multifileClassWithInternal.kt
new file mode 100644
index 00000000000..936b887daa8
--- /dev/null
+++ b/compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWithInternal/multifileClassWithInternal.kt
@@ -0,0 +1 @@
+fun box(): String = Baz.baz()
\ No newline at end of file
diff --git a/compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWithPrivate/Baz.java b/compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWithPrivate/Baz.java
new file mode 100644
index 00000000000..d5fd7bcb24a
--- /dev/null
+++ b/compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWithPrivate/Baz.java
@@ -0,0 +1,5 @@
+public class Baz {
+    public static String baz() {
+        return Util.foo() + Util.bar();
+    }
+}
\ No newline at end of file
diff --git a/compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWithPrivate/bar.kt b/compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWithPrivate/bar.kt
new file mode 100644
index 00000000000..a220905840a
--- /dev/null
+++ b/compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWithPrivate/bar.kt
@@ -0,0 +1,5 @@
+@file:JvmName("Util")
+@file:JvmMultifileClass
+public fun bar(): String = barx()
+
+private fun barx(): String = "K"
\ No newline at end of file
diff --git a/compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWithPrivate/foo.kt b/compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWithPrivate/foo.kt
new file mode 100644
index 00000000000..92b45cb2dc2
--- /dev/null
+++ b/compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWithPrivate/foo.kt
@@ -0,0 +1,5 @@
+@file:JvmName("Util")
+@file:JvmMultifileClass
+public fun foo(): String = foox()
+
+private fun foox(): String = "O"
\ No newline at end of file
diff --git a/compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWithPrivate/multifileClassWithPrivate.kt b/compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWithPrivate/multifileClassWithPrivate.kt
new file mode 100644
index 00000000000..936b887daa8
--- /dev/null
+++ b/compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWithPrivate/multifileClassWithPrivate.kt
@@ -0,0 +1 @@
+fun box(): String = Baz.baz()
\ No newline at end of file
diff --git a/compiler/testData/codegen/boxWithStdlib/platformNames/multifileClass.kt b/compiler/testData/codegen/boxWithStdlib/platformNames/multifileClass.kt
new file mode 100644
index 00000000000..5f5a1bf24ab
--- /dev/null
+++ b/compiler/testData/codegen/boxWithStdlib/platformNames/multifileClass.kt
@@ -0,0 +1,10 @@
+// NB this multifile class should be called "TestPackage" due to the way codegen box tests work.
+@file:JvmName("TestPackage")
+@file:JvmMultifileClass
+package test
+
+fun foo(): String = bar()
+fun bar(): String = qux()
+fun qux(): String = "OK"
+
+fun box(): String = foo()
\ No newline at end of file
diff --git a/compiler/tests/org/jetbrains/kotlin/codegen/generated/BlackBoxWithJavaCodegenTestGenerated.java b/compiler/tests/org/jetbrains/kotlin/codegen/generated/BlackBoxWithJavaCodegenTestGenerated.java
index 939ebd540f1..a9dc672daf2 100644
--- a/compiler/tests/org/jetbrains/kotlin/codegen/generated/BlackBoxWithJavaCodegenTestGenerated.java
+++ b/compiler/tests/org/jetbrains/kotlin/codegen/generated/BlackBoxWithJavaCodegenTestGenerated.java
@@ -135,6 +135,24 @@ public class BlackBoxWithJavaCodegenTestGenerated extends AbstractBlackBoxCodege
             doTestWithJava(fileName);
         }
 
+        @TestMetadata("multifileClassWith2Files")
+        public void testMultifileClassWith2Files() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWith2Files/");
+            doTestWithJava(fileName);
+        }
+
+        @TestMetadata("multifileClassWithInternal")
+        public void testMultifileClassWithInternal() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWithInternal/");
+            doTestWithJava(fileName);
+        }
+
+        @TestMetadata("multifileClassWithPrivate")
+        public void testMultifileClassWithPrivate() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/boxWithJava/fileClasses/multifileClassWithPrivate/");
+            doTestWithJava(fileName);
+        }
+
         @TestMetadata("simple")
         public void testSimple() throws Exception {
             String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/boxWithJava/fileClasses/simple/");
diff --git a/compiler/tests/org/jetbrains/kotlin/codegen/generated/BlackBoxWithStdlibCodegenTestGenerated.java b/compiler/tests/org/jetbrains/kotlin/codegen/generated/BlackBoxWithStdlibCodegenTestGenerated.java
index 6f1d671c785..a6b911c4d0f 100644
--- a/compiler/tests/org/jetbrains/kotlin/codegen/generated/BlackBoxWithStdlibCodegenTestGenerated.java
+++ b/compiler/tests/org/jetbrains/kotlin/codegen/generated/BlackBoxWithStdlibCodegenTestGenerated.java
@@ -2239,6 +2239,12 @@ public class BlackBoxWithStdlibCodegenTestGenerated extends AbstractBlackBoxCode
             doTestWithStdlib(fileName);
         }
 
+        @TestMetadata("multifileClass.kt")
+        public void testMultifileClass() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/boxWithStdlib/platformNames/multifileClass.kt");
+            doTestWithStdlib(fileName);
+        }
+
         @TestMetadata("propertyName.kt")
         public void testPropertyName() throws Exception {
             String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/boxWithStdlib/platformNames/propertyName.kt");