diff --git a/jso/impl/src/main/java/org/teavm/jso/impl/JSWrapper.java b/jso/impl/src/main/java/org/teavm/jso/impl/JSWrapper.java
index 3ff556744..bf81f91df 100644
--- a/jso/impl/src/main/java/org/teavm/jso/impl/JSWrapper.java
+++ b/jso/impl/src/main/java/org/teavm/jso/impl/JSWrapper.java
@@ -35,6 +35,7 @@ public final class JSWrapper {
             ? JSMap.create() : null;
     private static final JSMap<JSNumber, JSWeakRef<JSObject>> numberWrappers = JSWeakRef.isSupported()
             ? JSMap.create() : null;
+    private static JSWeakRef<JSObject> undefinedWrapper;
     private static final JSFinalizationRegistry stringFinalizationRegistry;
     private static final JSFinalizationRegistry numberFinalizationRegistry;
     private static int hashCodeGen;
@@ -59,12 +60,13 @@ public final class JSWrapper {
             return null;
         }
         var js = directJavaToJs(o);
-        if (isJSImplementation(o)) {
+        var type = JSObjects.typeOf(js);
+        var isObject = type.equals("object") || type.equals("function");
+        if (isObject && isJSImplementation(o)) {
             return o;
         }
         if (wrappers != null) {
-            var type = JSObjects.typeOf(js);
-            if (type.equals("object") || type.equals("function")) {
+            if (isObject) {
                 var existingRef = get(wrappers, js);
                 var existing = !JSObjects.isUndefined(existingRef) ? deref(existingRef) : JSObjects.undefined();
                 if (JSObjects.isUndefined(existing)) {
@@ -100,6 +102,17 @@ public final class JSWrapper {
                 } else {
                     return jsToWrapper(existing);
                 }
+            } else if (type.equals("undefined")) {
+                var existingRef = undefinedWrapper;
+                var existing = existingRef != null ? deref(existingRef) : JSObjects.undefined();
+                if (JSObjects.isUndefined(existing)) {
+                    var wrapper = new JSWrapper(js);
+                    var wrapperAsJs = wrapperToJs(wrapper);
+                    undefinedWrapper = createWeakRef(wrapperAsJs);
+                    return wrapper;
+                } else {
+                    return jsToWrapper(existing);
+                }
             }
         }
         return new JSWrapper(js);
diff --git a/tests/src/test/java/org/teavm/jso/test/JSWrapperTest.java b/tests/src/test/java/org/teavm/jso/test/JSWrapperTest.java
index 1d3bd268f..5067ee228 100644
--- a/tests/src/test/java/org/teavm/jso/test/JSWrapperTest.java
+++ b/tests/src/test/java/org/teavm/jso/test/JSWrapperTest.java
@@ -311,6 +311,16 @@ public class JSWrapperTest {
         }));
     }
 
+    @Test
+    public void wrapUndefined() {
+        field1 = JSObjects.undefined();
+        assertEquals("undefined", field1.toString());
+        assertEquals(JSObjects.undefined(), field1);
+        assertSame(JSObjects.undefined(), field1);
+        assertTrue(field1 instanceof JSObject);
+        assertTrue(JSObjects.isUndefined(field1));
+    }
+
     private void callSetProperty(Object instance, Object o) {
         setProperty(instance, "foo", o);
     }