diff --git a/Libraries/LibJS/Bytecode/Interpreter.cpp b/Libraries/LibJS/Bytecode/Interpreter.cpp
index 96cc3387cdb..a462c6543f0 100644
--- a/Libraries/LibJS/Bytecode/Interpreter.cpp
+++ b/Libraries/LibJS/Bytecode/Interpreter.cpp
@@ -1732,6 +1732,8 @@ inline ThrowCompletionOr<Object*> get_object_property_iterator(VM& vm, Value val
                 continue;
 
             auto descriptor = TRY(object_to_check->internal_get_own_property(property_key));
+            if (!descriptor.has_value())
+                continue;
             if (!*descriptor->enumerable)
                 non_enumerable_properties.set(move(property_key));
             else
diff --git a/Libraries/LibJS/Tests/builtins/Proxy/iterate-over-proxy.js b/Libraries/LibJS/Tests/builtins/Proxy/iterate-over-proxy.js
new file mode 100644
index 00000000000..e6baadbe9aa
--- /dev/null
+++ b/Libraries/LibJS/Tests/builtins/Proxy/iterate-over-proxy.js
@@ -0,0 +1,12 @@
+test("iterate over bogus proxy", () => {
+    expect(() => {
+        let proxy = new Proxy([123], {
+            getOwnPropertyDescriptor: function (p) {
+                return undefined;
+            },
+        });
+
+        for (const p in proxy) {
+        }
+    }).toThrow();
+});