diff --git a/docs/simplesamlphp-reference-idp-hosted.md b/docs/simplesamlphp-reference-idp-hosted.md
index 25d7fc7259ffbdd5ce28f980f52e7d6bb91fcf6b..7b7740961a1830d7834dcbb86c4ae577b444f860 100644
--- a/docs/simplesamlphp-reference-idp-hosted.md
+++ b/docs/simplesamlphp-reference-idp-hosted.md
@@ -18,7 +18,7 @@ Both files have the following format:
     ];
     /* ... */
 
-The entity ID should be an URI.
+The entity ID must be a URI.
 
 The `host` option is the hostname of the IdP, and will be used to
 select the correct configuration. One entry in the metadata-list can