diff --git a/rhino/build.gradle b/rhino/build.gradle
index 9cab2d4527..92d76d949f 100644
--- a/rhino/build.gradle
+++ b/rhino/build.gradle
@@ -2,6 +2,9 @@ plugins {
     id 'rhino.library-conventions'
 }
 
+dependencies {
+    implementation "org.jetbrains.kotlin:kotlin-metadata-jvm:2.1.0"
+}
 
 publishing {
     publications {
diff --git a/rhino/src/main/java/module-info.java b/rhino/src/main/java/module-info.java
index 90cad354c6..642727d763 100644
--- a/rhino/src/main/java/module-info.java
+++ b/rhino/src/main/java/module-info.java
@@ -14,4 +14,6 @@
     requires java.compiler;
     requires jdk.dynalink;
     requires transitive java.desktop;
+    requires kotlin.metadata.jvm;
+    requires kotlin.stdlib;
 }
diff --git a/rhino/src/main/java/org/mozilla/javascript/AccessorSlot.java b/rhino/src/main/java/org/mozilla/javascript/AccessorSlot.java
index 02f26b2f6a..f8607967bc 100644
--- a/rhino/src/main/java/org/mozilla/javascript/AccessorSlot.java
+++ b/rhino/src/main/java/org/mozilla/javascript/AccessorSlot.java
@@ -235,8 +235,9 @@ public boolean setValue(Object value, Scriptable owner, Scriptable start) {
             // XXX: cache tag since it is already calculated in
             // defineProperty ?
             Class<?> valueType = pTypes[pTypes.length - 1];
+            boolean isNullable = member.argNullability[pTypes.length - 1];
             int tag = FunctionObject.getTypeTag(valueType);
-            Object actualArg = FunctionObject.convertArg(cx, start, value, tag);
+            Object actualArg = FunctionObject.convertArg(cx, start, value, tag, isNullable);
 
             if (member.delegateTo == null) {
                 member.invoke(start, new Object[] {actualArg});
diff --git a/rhino/src/main/java/org/mozilla/javascript/FunctionObject.java b/rhino/src/main/java/org/mozilla/javascript/FunctionObject.java
index e5fa959d15..e297ac5653 100644
--- a/rhino/src/main/java/org/mozilla/javascript/FunctionObject.java
+++ b/rhino/src/main/java/org/mozilla/javascript/FunctionObject.java
@@ -163,20 +163,29 @@ public static int getTypeTag(Class<?> type) {
         return JAVA_UNSUPPORTED_TYPE;
     }
 
-    public static Object convertArg(Context cx, Scriptable scope, Object arg, int typeTag) {
+    public static Object convertArg(
+            Context cx, Scriptable scope, Object arg, int typeTag, boolean isNullable) {
         switch (typeTag) {
             case JAVA_STRING_TYPE:
                 if (arg instanceof String) return arg;
-                return ScriptRuntime.toString(arg);
+                return (arg == null && isNullable) ? null : ScriptRuntime.toString(arg);
             case JAVA_INT_TYPE:
                 if (arg instanceof Integer) return arg;
-                return Integer.valueOf(ScriptRuntime.toInt32(arg));
+                return (arg == null && isNullable)
+                        ? null
+                        : Integer.valueOf(ScriptRuntime.toInt32(arg));
             case JAVA_BOOLEAN_TYPE:
                 if (arg instanceof Boolean) return arg;
-                return ScriptRuntime.toBoolean(arg) ? Boolean.TRUE : Boolean.FALSE;
+                if (arg == null && isNullable) {
+                    return null;
+                } else {
+                    return ScriptRuntime.toBoolean(arg) ? Boolean.TRUE : Boolean.FALSE;
+                }
             case JAVA_DOUBLE_TYPE:
                 if (arg instanceof Double) return arg;
-                return Double.valueOf(ScriptRuntime.toNumber(arg));
+                return (arg == null && isNullable)
+                        ? null
+                        : Double.valueOf(ScriptRuntime.toNumber(arg));
             case JAVA_SCRIPTABLE_TYPE:
                 return ScriptRuntime.toObjectOrNull(cx, arg, scope);
             case JAVA_OBJECT_TYPE:
@@ -321,7 +330,7 @@ void initAsConstructor(Scriptable scope, Scriptable prototype, int attributes) {
 
     /**
      * @deprecated Use {@link #getTypeTag(Class)} and {@link #convertArg(Context, Scriptable,
-     *     Object, int)} for type conversion.
+     *     Object, int, boolean)} for type conversion.
      */
     @Deprecated
     public static Object convertArg(Context cx, Scriptable scope, Object arg, Class<?> desired) {
@@ -329,7 +338,7 @@ public static Object convertArg(Context cx, Scriptable scope, Object arg, Class<
         if (tag == JAVA_UNSUPPORTED_TYPE) {
             throw Context.reportRuntimeErrorById("msg.cant.convert", desired.getName());
         }
-        return convertArg(cx, scope, arg, tag);
+        return convertArg(cx, scope, arg, tag, false);
     }
 
     /**
@@ -401,7 +410,8 @@ public Object call(Context cx, Scriptable scope, Scriptable thisObj, Object[] ar
                 invokeArgs = args;
                 for (int i = 0; i != parmsLength; ++i) {
                     Object arg = args[i];
-                    Object converted = convertArg(cx, scope, arg, typeTags[i]);
+                    Object converted =
+                            convertArg(cx, scope, arg, typeTags[i], member.argNullability[i]);
                     if (arg != converted) {
                         if (invokeArgs == args) {
                             invokeArgs = args.clone();
@@ -415,7 +425,8 @@ public Object call(Context cx, Scriptable scope, Scriptable thisObj, Object[] ar
                 invokeArgs = new Object[parmsLength];
                 for (int i = 0; i != parmsLength; ++i) {
                     Object arg = (i < argsLength) ? args[i] : Undefined.instance;
-                    invokeArgs[i] = convertArg(cx, scope, arg, typeTags[i]);
+                    invokeArgs[i] =
+                            convertArg(cx, scope, arg, typeTags[i], member.argNullability[i]);
                 }
             }
 
diff --git a/rhino/src/main/java/org/mozilla/javascript/MemberBox.java b/rhino/src/main/java/org/mozilla/javascript/MemberBox.java
index 3035950a2b..6ccc3093ff 100644
--- a/rhino/src/main/java/org/mozilla/javascript/MemberBox.java
+++ b/rhino/src/main/java/org/mozilla/javascript/MemberBox.java
@@ -6,6 +6,8 @@
 
 package org.mozilla.javascript;
 
+import static kotlin.metadata.Attributes.isNullable;
+
 import java.io.IOException;
 import java.io.ObjectInputStream;
 import java.io.ObjectOutputStream;
@@ -15,6 +17,13 @@
 import java.lang.reflect.Member;
 import java.lang.reflect.Method;
 import java.lang.reflect.Modifier;
+import java.util.List;
+import java.util.Optional;
+import kotlin.Metadata;
+import kotlin.metadata.KmClass;
+import kotlin.metadata.KmFunction;
+import kotlin.metadata.KmValueParameter;
+import kotlin.metadata.jvm.KotlinClassMetadata;
 
 /**
  * Wrapper class for Method and Constructor instances to cache getParameterTypes() results, recover
@@ -27,6 +36,7 @@ final class MemberBox implements Serializable {
 
     private transient Member memberObject;
     transient Class<?>[] argTypes;
+    transient boolean[] argNullability;
     transient boolean vararg;
 
     transient Function asGetterFunction;
@@ -44,12 +54,56 @@ final class MemberBox implements Serializable {
     private void init(Method method) {
         this.memberObject = method;
         this.argTypes = method.getParameterTypes();
+        this.argNullability = getParameterNullability(method);
         this.vararg = method.isVarArgs();
     }
 
+    private boolean[] getParameterNullability(Method method) {
+        boolean[] result = new boolean[method.getParameters().length];
+        Metadata metadata = method.getDeclaringClass().getAnnotation(Metadata.class);
+        if (metadata != null) {
+            result = getParameterNullabilityFromKotlinMetadata(metadata, method.getName(), result);
+        }
+        return result;
+    }
+
+    private boolean[] getParameterNullability(Constructor<?> constructor) {
+        boolean[] result = new boolean[constructor.getParameters().length];
+        Metadata metadata = constructor.getDeclaringClass().getAnnotation(Metadata.class);
+        if (metadata != null) {
+            result =
+                    getParameterNullabilityFromKotlinMetadata(
+                            metadata, constructor.getName(), result);
+        }
+        return result;
+    }
+
+    private boolean[] getParameterNullabilityFromKotlinMetadata(
+            Metadata metadata, String methodName, boolean[] fallback) {
+        KotlinClassMetadata.Class kMetadata =
+                (KotlinClassMetadata.Class) KotlinClassMetadata.readLenient(metadata);
+        KmClass clazz = kMetadata.getKmClass();
+        Optional<KmFunction> function =
+                clazz.getFunctions().stream()
+                        .filter(f -> f.getName().equals(methodName))
+                        .findFirst();
+        if (function.isPresent()) {
+            List<KmValueParameter> params = function.get().getValueParameters();
+            boolean[] result = new boolean[params.size()];
+            int index = 0;
+            for (KmValueParameter parameter : params) {
+                result[index++] = isNullable(parameter.getType());
+            }
+            return result;
+        } else {
+            return fallback;
+        }
+    }
+
     private void init(Constructor<?> constructor) {
         this.memberObject = constructor;
         this.argTypes = constructor.getParameterTypes();
+        this.argNullability = getParameterNullability(constructor);
         this.vararg = constructor.isVarArgs();
     }
 
@@ -184,7 +238,8 @@ public Object call(
                                                     thisObj,
                                                     originalArgs[0],
                                                     FunctionObject.getTypeTag(
-                                                            nativeSetter.argTypes[0]))
+                                                            nativeSetter.argTypes[0]),
+                                                    nativeSetter.argNullability[0])
                                             : Undefined.instance;
                             if (nativeSetter.delegateTo == null) {
                                 setterThis = thisObj;