diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2f1a59b6..77fa4184 100755
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+# 5.5.2 (next)
+
+- Fix: Empty Constructor (was requiring at least an empyt object if used with only class fileds definitions)
+
 # 5.5.1 (next)
 
 - Introduced `preserveDeletedFieldsValues` form option (disabled by default).
diff --git a/src/Form.ts b/src/Form.ts
index 5d92f7e9..43e2c7c2 100755
--- a/src/Form.ts
+++ b/src/Form.ts
@@ -22,7 +22,7 @@ export default class Form extends Base implements FormInterface {
   debouncedValidation: any = null;
 
   constructor(
-    setup: FieldsDefinitions,
+    setup: FieldsDefinitions = {},
     {
       name = "",
       options = {},
diff --git a/src/State.ts b/src/State.ts
index 4dd89cc1..8394ed90 100755
--- a/src/State.ts
+++ b/src/State.ts
@@ -60,7 +60,7 @@ export default class State implements StateInterface {
     this.observeOptions();
   }
 
-  initProps(initial: any) {
+  initProps(initial: any = {}) {
     const initialProps: any = _.pick(initial, [
       ...props.separated,
       ...props.validation,
diff --git a/tests/data/_.fixes.ts b/tests/data/_.fixes.ts
index f31ba43e..b6827072 100755
--- a/tests/data/_.fixes.ts
+++ b/tests/data/_.fixes.ts
@@ -1,6 +1,8 @@
 /**
   FIXES
 */
+import $formEmptyConstructor from "./forms/form.empty.constructor";
+
 import $A from "./forms/fixes/form.a";
 import $B from "./forms/fixes/form.b";
 import $C from "./forms/fixes/form.c";
@@ -42,6 +44,7 @@ import $585 from "./forms/fixes/form.585";
 import $531 from "./forms/fixes/form.531";
 
 export default {
+  $formEmptyConstructor,
   $A,
   $B,
   $C,
diff --git a/tests/data/forms/form.empty.constructor.ts b/tests/data/forms/form.empty.constructor.ts
new file mode 100644
index 00000000..4c8b1758
--- /dev/null
+++ b/tests/data/forms/form.empty.constructor.ts
@@ -0,0 +1,4 @@
+import MobxReactForm from "../../../src";
+
+// EMPTY CONSTRUCTOR
+export default new MobxReactForm(); // do not change!
\ No newline at end of file
diff --git a/tests/fixes.props.ts b/tests/fixes.props.ts
index d2c7d9c2..dc040478 100755
--- a/tests/fixes.props.ts
+++ b/tests/fixes.props.ts
@@ -2,6 +2,11 @@ import { expect } from 'chai';
 
 import $ from './data/_.fixes'; // FORMS
 
+describe('Check Fixes $E props check', () => {
+  it('$formEmptyConstrcutor size should be equal 0', () =>
+    expect($.$formEmptyConstructor.size).to.be.equal(0));
+});
+
 
 describe('Check Fixes $E props check', () => {
   it('$E places extra should be array', () =>