diff --git a/src/api/client_server/account.rs b/src/api/client_server/account.rs
index 46551305..c2e251ac 100644
--- a/src/api/client_server/account.rs
+++ b/src/api/client_server/account.rs
@@ -86,6 +86,17 @@ pub async fn register_route(body: Ruma<register::v3::Request>) -> Result<registe
 
     let is_guest = body.kind == RegistrationKind::Guest;
 
+    if is_guest
+        && (!services().globals.allow_guest_registration()
+            || !services().globals.allow_registration())
+    {
+        info!("Guest registration disabled / registration fully disabled, rejecting guest registration, initial device name: {:?}", body.initial_device_display_name);
+        return Err(Error::BadRequest(
+            ErrorKind::GuestAccessForbidden,
+            "Guest registration is disabled.",
+        ));
+    }
+
     let user_id = match (&body.username, is_guest) {
         (Some(username), false) => {
             let proposed_user_id = UserId::parse_with_server_name(
diff --git a/src/config/mod.rs b/src/config/mod.rs
index c6c2646e..21cf6bf9 100644
--- a/src/config/mod.rs
+++ b/src/config/mod.rs
@@ -119,6 +119,9 @@ pub struct Config {
     #[serde(default = "false_fn")]
     pub zstd_compression: bool,
 
+    #[serde(default = "false_fn")]
+    pub allow_guest_registration: bool,
+
     #[serde(flatten)]
     pub catchall: BTreeMap<String, IgnoredAny>,
 }
@@ -195,6 +198,10 @@ impl fmt::Display for Config {
                 &self.max_concurrent_requests.to_string(),
             ),
             ("Allow registration", &self.allow_registration.to_string()),
+            (
+                "Allow guest registration",
+                &self.allow_guest_registration.to_string(),
+            ),
             (
                 "Enabled lightning bolt",
                 &self.enable_lightning_bolt.to_string(),
diff --git a/src/service/globals/mod.rs b/src/service/globals/mod.rs
index 21072d40..4df22b1b 100644
--- a/src/service/globals/mod.rs
+++ b/src/service/globals/mod.rs
@@ -295,6 +295,10 @@ impl Service {
         self.config.allow_registration
     }
 
+    pub fn allow_guest_registration(&self) -> bool {
+        self.config.allow_guest_registration
+    }
+
     pub fn allow_encryption(&self) -> bool {
         self.config.allow_encryption
     }