diff --git a/docs/usage/configuration/config_documentation.md b/docs/usage/configuration/config_documentation.md
index ef73284e42..d29de090b2 100644
--- a/docs/usage/configuration/config_documentation.md
+++ b/docs/usage/configuration/config_documentation.md
@@ -2190,9 +2190,9 @@ This setting has the following sub-options:
 
 * `enabled` (boolean): Enables the media redirect feature. If enabled, you must specify a `media_redirect.secret` or `media_redirect.secret_path`. Defaults to `false`.
 
-* `secret` (string): Secret used to sign media redirect URLs. This must be set if `media_redirect.enabled` is set. Defaults to `null`.
+* `secret` (string|null): Secret used to sign media redirect URLs. This must be set if `media_redirect.enabled` is set. Defaults to `null`.
 
-* `secret_path` (string): An alternative to `media_redirect.secret` that specifies a file containing the secret. Defaults to `null`.
+* `secret_path` (string|null): An alternative to `media_redirect.secret` that specifies a file containing the secret. Defaults to `null`.
 
 * `ttl` (duration): How long the redirect URLs should be valid for. Defaults to `"10m"`.
 
diff --git a/schema/synapse-config.schema.yaml b/schema/synapse-config.schema.yaml
index 374cf3d0f7..97b7c11573 100644
--- a/schema/synapse-config.schema.yaml
+++ b/schema/synapse-config.schema.yaml
@@ -2448,13 +2448,13 @@ properties:
           `media_redirect.secret` or `media_redirect.secret_path`.
         default: false
       secret:
-        type: string
+        type: ["string", "null"]
         description: >-
           Secret used to sign media redirect URLs. This must be set if
           `media_redirect.enabled` is set.
         default: null
       secret_path:
-        type: string
+        type: ["string", "null"]
         description: >-
           An alternative to `media_redirect.secret` that specifies a file
           containing the secret.