diff --git a/HISTORY.rst b/HISTORY.rst
index 0ffcc9cd78e243b52953611f1c42b542b9eaffd1_SElTVE9SWS5yc3Q=..0d18b68e90f1323aa3b0c5953f2179476118f69c_SElTVE9SWS5yc3Q= 100644
--- a/HISTORY.rst
+++ b/HISTORY.rst
@@ -1,6 +1,9 @@
 Release history
 ===============
 
+0.4.0 (2022-01-25)
+==================
+
 - wpd engine: almost complete rewrite of the engine. Should be more stable and
   handler big loads properly.
 - pooled engine: add an engine wrapper that runs multiple worker. It allow a
diff --git a/restapi/doc.go b/restapi/doc.go
index 0ffcc9cd78e243b52953611f1c42b542b9eaffd1_cmVzdGFwaS9kb2MuZ28=..0d18b68e90f1323aa3b0c5953f2179476118f69c_cmVzdGFwaS9kb2MuZ28= 100644
--- a/restapi/doc.go
+++ b/restapi/doc.go
@@ -10,7 +10,7 @@
 //    https
 //  Host: localhost
 //  BasePath: /api
-//  Version: 0.3.5
+//  Version: 0.4.0
 //
 //  Consumes:
 //    - application/io.orus.rednerd.v1+json
diff --git a/restapi/embedded_spec.go b/restapi/embedded_spec.go
index 0ffcc9cd78e243b52953611f1c42b542b9eaffd1_cmVzdGFwaS9lbWJlZGRlZF9zcGVjLmdv..0d18b68e90f1323aa3b0c5953f2179476118f69c_cmVzdGFwaS9lbWJlZGRlZF9zcGVjLmdv 100644
--- a/restapi/embedded_spec.go
+++ b/restapi/embedded_spec.go
@@ -33,7 +33,7 @@
   "info": {
     "description": "The Rednerd rendering server. For a list of available rendering engines\nand their options, see \u003ca href=\"/docs/engines\"\u003eRednerd Engines\u003c/a\u003e.\n",
     "title": "Rednerd API",
-    "version": "0.3.5"
+    "version": "0.4.0"
   },
   "basePath": "/api",
   "paths": {
@@ -1086,7 +1086,7 @@
   "info": {
     "description": "The Rednerd rendering server. For a list of available rendering engines\nand their options, see \u003ca href=\"/docs/engines\"\u003eRednerd Engines\u003c/a\u003e.\n",
     "title": "Rednerd API",
-    "version": "0.3.5"
+    "version": "0.4.0"
   },
   "basePath": "/api",
   "paths": {
diff --git a/swagger.yaml b/swagger.yaml
index 0ffcc9cd78e243b52953611f1c42b542b9eaffd1_c3dhZ2dlci55YW1s..0d18b68e90f1323aa3b0c5953f2179476118f69c_c3dhZ2dlci55YW1s 100644
--- a/swagger.yaml
+++ b/swagger.yaml
@@ -6,7 +6,7 @@
     and their options, see <a href="/docs/engines">Rednerd Engines</a>.
 
   title: Rednerd API
-  version: 0.3.5
+  version: 0.4.0
 consumes:
 - application/io.orus.rednerd.v1+json
 - application/json