diff --git a/configuration.md b/configuration.md
index cad473e..192f305 100644
--- a/configuration.md
+++ b/configuration.md
@@ -100,7 +100,7 @@ Note that any field not specified in the configuration will use its default valu
     - This is a private key, don't share it.
 - `MulticastInterfaces`
     - A list of regex strings for matching which interfaces to enable multicast peer discovery on. Interfaces that don't match any of the provided regexes are ignored.
-    - The default value (an empty string) matches all interfaces.
+    - The default value (`.*`) matches all interfaces.
     - This is also useful if you want to prevent accidental peering over a layer 2 VPN running on top of Yggdrasil.
 - `IfName`
     - The name of the `tun` or `tap` network interface to create or use. Applications send packets over this interface to use the network.