diff --git a/CHANGES.md b/CHANGES.md
index cc073fb..5f2bfff 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -3,6 +3,12 @@
 Changelog
 =========
 
+Version 0.4.0
+-------------
+
+To be released.
+
+
 Version 0.3.0
 -------------
 
diff --git a/deno.json b/deno.json
index 11398b0..2d84f0b 100644
--- a/deno.json
+++ b/deno.json
@@ -1,6 +1,6 @@
 {
   "name": "@fedify/markdown-it-hashtag",
-  "version": "0.3.0",
+  "version": "0.4.0",
   "exports": "./mod.ts",
   "imports": {
     "@deno/dnt": "jsr:@deno/dnt@^0.41.1",