diff --git a/model/KeyAction.ts b/model/KeyAction.ts
index 0634546e..229eb16b 100644
--- a/model/KeyAction.ts
+++ b/model/KeyAction.ts
@@ -6,30 +6,22 @@ class KeyAction {
     static fromJsObject(jsObject: any): KeyAction {
         switch (jsObject.keyActionType) {
             case KeystrokeAction.actionTypeString:
-                let keyActionNone = new KeyActionNone();
-                keyActionNone.fromJsObject(jsObject);
-                return keyActionNone;
+                return new KeyActionNone().fromJsObject(jsObject);
             case KeystrokeAction.actionTypeString:
-                let keystrokeAction = new KeystrokeAction();
-                keystrokeAction.fromJsObject(jsObject);
-                return keystrokeAction;
+                return new KeystrokeAction().fromJsObject(jsObject);
             default:
                 throw 'Unknown KeyAction actionType "${jsObject.actionType}"';
         }
     }
 
-    static fromBinary(buffer: UhkBuffer) {
+    static fromBinary(buffer: UhkBuffer): KeyAction {
         let keyActionFirstByte = buffer.readUInt8();
         buffer.backtrack();
 
         if (KeystrokeAction.isScancodeValid(keyActionFirstByte)) {
-            let keystrokeAction = new KeystrokeAction();
-            keystrokeAction.fromBinary(buffer);
-            return keystrokeAction;
+            return new KeystrokeAction().fromBinary(buffer);
         } else if (keyActionFirstByte === KeyActionNone.keyActionNoneId) {
-            let keyActionNone = new KeyActionNone();
-            keyActionNone.fromBinary(buffer);
-            return keyActionNone;
+            return new KeyActionNone().fromBinary(buffer);
         } else {
             throw 'Unknown KeyAction first byte "${keyActionFirstByte}"';
         }
diff --git a/model/KeyActionNone.ts b/model/KeyActionNone.ts
index 78a55625..6993182b 100644
--- a/model/KeyActionNone.ts
+++ b/model/KeyActionNone.ts
@@ -1,18 +1,19 @@
 /// <reference path="KeyAction.ts" />
 /// <reference path="Serializable.ts" />
 
-class KeyActionNone extends KeyAction implements Serializable {
+class KeyActionNone extends KeyAction implements Serializable<KeyActionNone> {
     static actionTypeString = 'none';
     static keyActionNoneId = 0;
     static keyActionNoneParam = 0;
 
-    fromJsObject(jsObject: any) {
+    fromJsObject(jsObject: any): KeyActionNone {
         if (jsObject.actionType !== 'none') {
             throw 'KeyActionNone: The actionType is not "none"';
         }
+        return this;
     }
 
-    fromBinary(buffer: UhkBuffer) {
+    fromBinary(buffer: UhkBuffer): KeyActionNone {
         let keyActionId = buffer.readUInt8();
         if (keyActionId !== KeyActionNone.keyActionNoneId) {
             throw 'KeyActionNone: id is ${keyActionId} instead of ${KeyActionNone.keyActionNoneId}';
@@ -22,6 +23,8 @@ class KeyActionNone extends KeyAction implements Serializable {
         if (keyActionParam !== KeyActionNone.keyActionNoneParam) {
             throw 'KeyActionNone: The param is ${keyActionParam} instead of ${KeyActionNone.keyActionNoneParam}';
         }
+
+        return this;
     }
 
     toJsObject(): any {
diff --git a/model/KeystrokeAction.ts b/model/KeystrokeAction.ts
index b34d53e9..b9592264 100644
--- a/model/KeystrokeAction.ts
+++ b/model/KeystrokeAction.ts
@@ -1,9 +1,9 @@
 /// <reference path="KeyAction.ts" />
 /// <reference path="Serializable.ts" />
 
-class KeystrokeAction extends KeyAction implements Serializable {
+class KeystrokeAction extends KeyAction implements Serializable<KeystrokeAction> {
 
-    static actionTypeString = 'keyStroke';
+    static actionTypeString = 'keystroke';
     static firstValidScancode = 1;
     static lastValidScancode = 231;
 
@@ -26,22 +26,24 @@ class KeystrokeAction extends KeyAction implements Serializable {
                scancode <= KeystrokeAction.lastValidScancode;
     }
 
-    fromJsObject(jsObject: any) {
+    fromJsObject(jsObject: any): KeystrokeAction {
         this.scancode = jsObject.scancode;
         this.modifierMask = jsObject.modifierMask;
+        return this;
     }
 
     toJsObject(): any {
         return {
-            keyActionType: 'keystroke',
+            keyActionType: KeystrokeAction.actionTypeString,
             scancode: this.scancode,
             modifierMask: this.modifierMask
         };
     }
 
-    fromBinary(buffer: UhkBuffer) {
+    fromBinary(buffer: UhkBuffer): KeystrokeAction {
         this.scancode = buffer.readUInt8();
         this.modifierMask = buffer.readUInt8();
+        return this;
     }
 
     toBinary(buffer: UhkBuffer) {
diff --git a/model/Serializable.ts b/model/Serializable.ts
index 48259cd9..59c77891 100644
--- a/model/Serializable.ts
+++ b/model/Serializable.ts
@@ -1,8 +1,8 @@
 /// <reference path="UhkBuffer.ts" />
 
-interface Serializable {
-    fromJsObject(jsObject: any);
-    fromBinary(buffer: UhkBuffer);
+interface Serializable<T> {
+    fromJsObject(jsObject: any): T;
+    fromBinary(buffer: UhkBuffer): T;
     toJsObject(): any;
     toBinary(buffer: UhkBuffer);
 }