diff --git a/Cargo.toml b/Cargo.toml
index e88a5734..8be909ce 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -11,8 +11,8 @@ repository = "https://github.com/ruma/ruma-api"
 version = "0.1.0"
 
 [dependencies]
-serde = "0.8.19"
+serde = "0.8.21"
 
 [dev-dependencies]
-ruma-identifiers = "0.5.0"
-serde_derive = "0.8.19"
+ruma-identifiers = "0.6.0"
+serde_derive = "0.8.21"
diff --git a/src/lib.rs b/src/lib.rs
index c1fd7667..08918723 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -88,7 +88,7 @@ pub trait Endpoint {
     type PathParams;
 
     /// Parameters supplied via the URL's query string.
-    type QueryParams;
+    type QueryParams: Deserialize + Serialize;
 
     /// The body of the response.
     type Response: Deserialize + Serialize;