diff --git a/changelogs/client_server/newsfragments/3327.breaking b/changelogs/client_server/newsfragments/3327.breaking
new file mode 100644
index 00000000..85c0da8b
--- /dev/null
+++ b/changelogs/client_server/newsfragments/3327.breaking
@@ -0,0 +1 @@
+Fix key_backup operation IDs in OpenAPI spec.
diff --git a/data/api/client-server/key_backup.yaml b/data/api/client-server/key_backup.yaml
index 7c42f6b5..73044c6d 100644
--- a/data/api/client-server/key_backup.yaml
+++ b/data/api/client-server/key_backup.yaml
@@ -375,7 +375,7 @@ paths:
       summary: Store a key in the backup.
       description: |-
         Store a key in the backup.
-      operationId: postRoomKeysKeyRoomIdSessionId
+      operationId: putRoomKeysBySessionId
       security:
         - accessToken: []
       parameters:
@@ -443,10 +443,10 @@ paths:
       tags:
         - End-to-end encryption
     get:
-      summary: Retrieve a key from the backup
+      summary: Retrieve a key from the backup.
       description: |-
         Retrieve a key from the backup.
-      operationId: getRoomKeysKeyRoomIdSessionId
+      operationId: getRoomKeysBySessionId
       security:
         - accessToken: []
       parameters:
@@ -488,10 +488,10 @@ paths:
           schema:
             "$ref": "definitions/errors/rate_limited.yaml"
     delete:
-      summary: Delete a key from the backup
+      summary: Delete a key from the backup.
       description: |-
         Delete a key from the backup.
-      operationId: deleteRoomKeysKeyRoomIdSessionId
+      operationId: deleteRoomKeysBySessionId
       security:
         - accessToken: []
       parameters:
@@ -551,8 +551,8 @@ paths:
     put:
       summary: Store several keys in the backup for a given room.
       description: |-
-        Store a key in the backup.
-      operationId: postRoomKeysKeyRoomId
+        Store several keys in the backup for a given room.
+      operationId: putRoomKeysByRoomId
       security:
         - accessToken: []
       parameters:
@@ -624,10 +624,10 @@ paths:
       tags:
         - End-to-end encryption
     get:
-      summary: Retrieve the keys from the backup for a given room
+      summary: Retrieve the keys from the backup for a given room.
       description: |-
-        Retrieve the keys from the backup for a given room
-      operationId: getRoomKeysKeyRoomId
+        Retrieve the keys from the backup for a given room.
+      operationId: getRoomKeysByRoomId
       security:
         - accessToken: []
       parameters:
@@ -667,10 +667,10 @@ paths:
           schema:
             "$ref": "definitions/errors/rate_limited.yaml"
     delete:
-      summary: Delete a key from the backup
+      summary: Delete the keys from the backup for a given room.
       description: |-
-        Delete a key from the backup.
-      operationId: deleteRoomKeysKeyRoomId
+        Delete the keys from the backup for a given room.
+      operationId: deleteRoomKeysByRoomId
       security:
         - accessToken: []
       parameters:
@@ -725,7 +725,7 @@ paths:
       summary: Store several keys in the backup.
       description: |-
         Store several keys in the backup.
-      operationId: postRoomKeysKey
+      operationId: putRoomKeys
       security:
         - accessToken: []
       parameters:
@@ -817,10 +817,10 @@ paths:
       tags:
         - End-to-end encryption
     get:
-      summary: Retrieve the keys from the backup for a given room
+      summary: Retrieve the keys from the backup.
       description: |-
-        Retrieve the keys from the backup for a given room
-      operationId: getRoomKeysKeyRoomId
+        Retrieve the keys from the backup.
+      operationId: getRoomKeys
       security:
         - accessToken: []
       parameters:
@@ -876,10 +876,10 @@ paths:
           schema:
             "$ref": "definitions/errors/rate_limited.yaml"
     delete:
-      summary: Delete a key from the backup
+      summary: Delete the keys from the backup.
       description: |-
-        Delete a key from the backup.
-      operationId: deleteRoomKeysKeyRoomId
+        Delete the keys from the backup.
+      operationId: deleteRoomKeys
       security:
         - accessToken: []
       parameters: