diff --git a/package.json b/package.json
index 163af0955..bae1ad521 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "gridstack",
-  "version": "6.0.1",
+  "version": "6.0.1-dev",
   "description": "TypeScript/JS lib for dashboard layout and creation, no external dependencies, with many wrappers (React, Angular, Vue, Ember, knockout...)",
   "main": "./dist/gridstack.js",
   "types": "./dist/gridstack.d.ts",
diff --git a/src/dd-base-impl.ts b/src/dd-base-impl.ts
index a1e77ffc5..0c56a29a0 100644
--- a/src/dd-base-impl.ts
+++ b/src/dd-base-impl.ts
@@ -1,5 +1,5 @@
 /**
- * dd-base-impl.ts 6.0.1
+ * dd-base-impl.ts 6.0.1-dev
  * Copyright (c) 2021-2022 Alain Dumesny - see GridStack root license
  */
 
diff --git a/src/dd-draggable.ts b/src/dd-draggable.ts
index 47c27dced..e56f908a8 100644
--- a/src/dd-draggable.ts
+++ b/src/dd-draggable.ts
@@ -1,5 +1,5 @@
 /**
- * dd-draggable.ts 6.0.1
+ * dd-draggable.ts 6.0.1-dev
  * Copyright (c) 2021-2022 Alain Dumesny - see GridStack root license
  */
 
diff --git a/src/dd-droppable.ts b/src/dd-droppable.ts
index 1ce5be5af..8d19f5e64 100644
--- a/src/dd-droppable.ts
+++ b/src/dd-droppable.ts
@@ -1,5 +1,5 @@
 /**
- * dd-droppable.ts 6.0.1
+ * dd-droppable.ts 6.0.1-dev
  * Copyright (c) 2021-2022 Alain Dumesny - see GridStack root license
  */
 
diff --git a/src/dd-element.ts b/src/dd-element.ts
index 57da38b8e..5973b152e 100644
--- a/src/dd-element.ts
+++ b/src/dd-element.ts
@@ -1,5 +1,5 @@
 /**
- * dd-elements.ts 6.0.1
+ * dd-elements.ts 6.0.1-dev
  * Copyright (c) 2021 Alain Dumesny - see GridStack root license
  */
 
diff --git a/src/dd-gridstack.ts b/src/dd-gridstack.ts
index ff2e61a13..1a7253955 100644
--- a/src/dd-gridstack.ts
+++ b/src/dd-gridstack.ts
@@ -1,5 +1,5 @@
 /**
- * dd-gridstack.ts 6.0.1
+ * dd-gridstack.ts 6.0.1-dev
  * Copyright (c) 2021 Alain Dumesny - see GridStack root license
  */
 
diff --git a/src/dd-manager.ts b/src/dd-manager.ts
index 5a40e5d8e..04ca39910 100644
--- a/src/dd-manager.ts
+++ b/src/dd-manager.ts
@@ -1,5 +1,5 @@
 /**
- * dd-manager.ts 6.0.1
+ * dd-manager.ts 6.0.1-dev
  * Copyright (c) 2021 Alain Dumesny - see GridStack root license
  */
 
diff --git a/src/dd-resizable-handle.ts b/src/dd-resizable-handle.ts
index 4330a341e..43c4af626 100644
--- a/src/dd-resizable-handle.ts
+++ b/src/dd-resizable-handle.ts
@@ -1,5 +1,5 @@
 /**
- * dd-resizable-handle.ts 6.0.1
+ * dd-resizable-handle.ts 6.0.1-dev
  * Copyright (c) 2021-2022 Alain Dumesny - see GridStack root license
  */
 
diff --git a/src/dd-resizable.ts b/src/dd-resizable.ts
index 508626f55..3bad5109f 100644
--- a/src/dd-resizable.ts
+++ b/src/dd-resizable.ts
@@ -1,5 +1,5 @@
 /**
- * dd-resizable.ts 6.0.1
+ * dd-resizable.ts 6.0.1-dev
  * Copyright (c) 2021-2022 Alain Dumesny - see GridStack root license
  */
 
diff --git a/src/dd-touch.ts b/src/dd-touch.ts
index b73bfb4f9..10b563483 100644
--- a/src/dd-touch.ts
+++ b/src/dd-touch.ts
@@ -1,5 +1,5 @@
 /**
- * touch.ts 6.0.1
+ * touch.ts 6.0.1-dev
  * Copyright (c) 2021 Alain Dumesny - see GridStack root license
  */
 
diff --git a/src/gridstack-engine.ts b/src/gridstack-engine.ts
index d536ccd23..b8e5c8ead 100644
--- a/src/gridstack-engine.ts
+++ b/src/gridstack-engine.ts
@@ -1,5 +1,5 @@
 /**
- * gridstack-engine.ts 6.0.1
+ * gridstack-engine.ts 6.0.1-dev
  * Copyright (c) 2021-2022 Alain Dumesny - see GridStack root license
  */
 
diff --git a/src/gridstack-poly.js b/src/gridstack-poly.js
index 934167236..1b4b4d728 100644
--- a/src/gridstack-poly.js
+++ b/src/gridstack-poly.js
@@ -1,5 +1,5 @@
 /**
- * gridstack-poly.ts 6.0.1 used for IE and older browser support (not supported in v2-v4.3.1, but again in v4.4)
+ * gridstack-poly.ts 6.0.1-dev used for IE and older browser support (not supported in v2-v4.3.1, but again in v4.4)
  * Copyright (c) 2021 Alain Dumesny - see GridStack root license
  */
 
diff --git a/src/gridstack.scss b/src/gridstack.scss
index 24c2dbb4e..cf35bc0f9 100644
--- a/src/gridstack.scss
+++ b/src/gridstack.scss
@@ -1,5 +1,5 @@
 /**
- * gridstack SASS styles 6.0.1
+ * gridstack SASS styles 6.0.1-dev
  * Copyright (c) 2021 Alain Dumesny - see GridStack root license
  */
 
diff --git a/src/gridstack.ts b/src/gridstack.ts
index 0e71b9a56..6f98132a2 100644
--- a/src/gridstack.ts
+++ b/src/gridstack.ts
@@ -1,5 +1,5 @@
 /*!
- * GridStack 6.0.1
+ * GridStack 6.0.1-dev
  * https://gridstackjs.com/
  *
  * Copyright (c) 2021-2022 Alain Dumesny
@@ -1515,7 +1515,7 @@ export class GridStack {
     return this;
   }
 
-  static GDRev = '6.0.1';
+  static GDRev = '6.0.1-dev';
 
   /*
    * drag&drop empty stubs that will be implemented in dd-gridstack.ts for non static grid
diff --git a/src/types.ts b/src/types.ts
index 8827d441c..1f9aa1e5f 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -1,5 +1,5 @@
 /**
- * types.ts 6.0.1
+ * types.ts 6.0.1-dev
  * Copyright (c) 2021 Alain Dumesny - see GridStack root license
  */
 
diff --git a/src/utils.ts b/src/utils.ts
index 3d564e84b..f94081ab0 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -1,5 +1,5 @@
 /**
- * utils.ts 6.0.1
+ * utils.ts 6.0.1-dev
  * Copyright (c) 2021 Alain Dumesny - see GridStack root license
  */