diff --git a/changelogs/internal/newsfragments/1562.clarification b/changelogs/internal/newsfragments/1562.clarification
new file mode 100644
index 00000000..6882cad1
--- /dev/null
+++ b/changelogs/internal/newsfragments/1562.clarification
@@ -0,0 +1 @@
+Make sure version in x-changedInMatrixVersion is a string.
diff --git a/data/api/client-server/definitions/client_event_without_room_id.yaml b/data/api/client-server/definitions/client_event_without_room_id.yaml
index 0decb6f3..d78dcc68 100644
--- a/data/api/client-server/definitions/client_event_without_room_id.yaml
+++ b/data/api/client-server/definitions/client_event_without_room_id.yaml
@@ -104,7 +104,7 @@ properties:
           by the local homeserver, and is only returned if the event is a state event,
           and the client has permission to see the previous content.
         x-changedInMatrixVersion:
-          1.2: |
+          "1.2": |
             Previously, this field was specified at the top level of returned
             events rather than in `unsigned` (with the exception of the [`GET
             .../notifications`](/client-server-api/#get_matrixclientv3notifications)
diff --git a/data/event-schemas/schema/m.call.hangup.yaml b/data/event-schemas/schema/m.call.hangup.yaml
index 65d697ab..0ca7fb65 100644
--- a/data/event-schemas/schema/m.call.hangup.yaml
+++ b/data/event-schemas/schema/m.call.hangup.yaml
@@ -35,7 +35,7 @@ properties:
           previous previous versions of the spec, so a missing value should be
           treated as `user_hangup`.
         x-changedInMatrixVersion:
-          1.7: |-
+          "1.7": |-
             Additional values were added.
         enum:
         - ice_timeout
diff --git a/data/event-schemas/schema/m.receipt.yaml b/data/event-schemas/schema/m.receipt.yaml
index c501d022..6062d31f 100644
--- a/data/event-schemas/schema/m.receipt.yaml
+++ b/data/event-schemas/schema/m.receipt.yaml
@@ -2,7 +2,7 @@ type: object
 title: Receipt Event
 description: Informs the client of new receipts.
 x-changedInMatrixVersion:
-    1.4: |
+    "1.4": |
         Added `m.read.private` receipts to the event's `content`.
 allOf:
     - $ref: "core-event-schema/event.yaml"
diff --git a/data/event-schemas/schema/m.room.encrypted.yaml b/data/event-schemas/schema/m.room.encrypted.yaml
index 84461013..95e05ff7 100644
--- a/data/event-schemas/schema/m.room.encrypted.yaml
+++ b/data/event-schemas/schema/m.room.encrypted.yaml
@@ -42,7 +42,7 @@ properties:
       sender_key:
         type: string
         x-changedInMatrixVersion:
-          1.3: |-
+          "1.3": |-
             Previously this field was required, however given it offers no additional
             security or privacy benefit it has been deprecated for Megolm messages.
             See [`m.megolm.v1.aes-sha2`](#mmegolmv1aes-sha2) for more information.
@@ -57,7 +57,7 @@ properties:
       device_id:
         type: string
         x-changedInMatrixVersion:
-          1.3: |-
+          "1.3": |-
             Previously this field was required for Megolm messages, however given it
             offers no additional security or privacy benefit it has been deprecated
             for Megolm messages. See [`m.megolm.v1.aes-sha2`](#mmegolmv1aes-sha2) for
diff --git a/data/event-schemas/schema/m.room_key_request.yaml b/data/event-schemas/schema/m.room_key_request.yaml
index acabe2d9..9894456e 100644
--- a/data/event-schemas/schema/m.room_key_request.yaml
+++ b/data/event-schemas/schema/m.room_key_request.yaml
@@ -24,7 +24,7 @@ properties:
           sender_key:
             type: string
             x-changedInMatrixVersion:
-              1.3: |-
+              "1.3": |-
                 Previously this field was required, however given it offers no additional
                 security or privacy benefit it has been deprecated. See [`m.megolm.v1.aes-sha2`](#mmegolmv1aes-sha2)
                 for more information.