diff --git a/source/migrations/r3-r4.postgresql.sql b/source/migrations/r3-r4.postgresql.sql
new file mode 100644
index 0000000..6366936
--- /dev/null
+++ b/source/migrations/r3-r4.postgresql.sql
@@ -0,0 +1,49 @@
+-- users
+
+ALTER TABLE
+    "users"
+ADD COLUMN
+    "dav_token" VARCHAR(255)
+;
+
+
+-- caldav_resources
+
+ALTER TABLE
+    "caldav_resources"
+RENAME TO
+    "ics_feed_resources"
+;
+
+ALTER TABLE
+    "ics_feed_resources"
+DROP COLUMN
+    "read_only"
+;
+
+ALTER TABLE
+    "ics_feed_resources"
+ADD COLUMN
+    "from_fucked_up_wordpress" BOOLEAN NOT NULL
+;
+
+COMMENT ON COLUMN
+    "resources"."kind"
+IS
+    '»local« | »ics_feed«'
+;
+
+COMMENT ON COLUMN
+    "resources"."sub_id"
+IS
+    'local_resources.id | ics_feed_resources.id'
+;
+
+
+-- _meta
+
+UPDATE
+    "_meta"
+SET
+    "revision" = 'r4'
+;
diff --git a/source/structure/r4.sindri.json b/source/structure/r4.sindri.json
index f3ae8db..9ccc04c 100644
--- a/source/structure/r4.sindri.json
+++ b/source/structure/r4.sindri.json
@@ -150,7 +150,7 @@
 			]
 		},
 		{
-			"name": "caldav_resources",
+			"name": "ics_feed_resources",
 			"key_field": {
 				"name": "id"
 			},
@@ -160,11 +160,6 @@
 					"type": "string_medium",
 					"nullable": false
 				},
-				{
-					"name": "read_only",
-					"type": "boolean",
-					"nullable": false
-				},
 				{
 					"name": "from_fucked_up_wordpress",
 					"type": "boolean",
@@ -184,13 +179,13 @@
 					"name": "kind",
 					"type": "string_short",
 					"nullable": false,
-					"description": "»local« | »caldav«"
+					"description": "»local« | »ics_feed«"
 				},
 				{
 					"name": "sub_id",
 					"type": "integer",
 					"nullable": false,
-					"description": "local_resources.id | caldav_resources.id"
+					"description": "local_resources.id | ics_feed_resources.id"
 				}
 			],
 			"constraints": [