diff --git a/crates/ruma-common/src/serde/raw.rs b/crates/ruma-common/src/serde/raw.rs
index 6466a02f..a76f075a 100644
--- a/crates/ruma-common/src/serde/raw.rs
+++ b/crates/ruma-common/src/serde/raw.rs
@@ -252,7 +252,7 @@ mod tests {
         assert_eq!(raw.get_field::<A<'_>>("a")?, Some(A { b: vec!["c"] }));
 
         assert_eq!(raw.get_field::<u8>("b")?, None);
-        assert!(raw.get_field::<u8>("a").is_err());
+        raw.get_field::<u8>("a").unwrap_err();
 
         Ok(())
     }
diff --git a/crates/ruma-common/tests/serde/url_deserialize.rs b/crates/ruma-common/tests/serde/url_deserialize.rs
index 6308e61a..650dde2b 100644
--- a/crates/ruma-common/tests/serde/url_deserialize.rs
+++ b/crates/ruma-common/tests/serde/url_deserialize.rs
@@ -55,7 +55,7 @@ fn deserialize_unit() {
     assert_eq!(urlencoded::from_str(""), Ok(()));
     assert_eq!(urlencoded::from_str("&"), Ok(()));
     assert_eq!(urlencoded::from_str("&&"), Ok(()));
-    assert!(urlencoded::from_str::<()>("first=23").is_err());
+    urlencoded::from_str::<()>("first=23").unwrap_err();
 }
 
 #[derive(Deserialize, Debug, PartialEq, Eq)]
@@ -152,7 +152,7 @@ fn deserialize_with_serde_attributes() {
 
 #[test]
 fn deserialize_nested_list() {
-    assert!(urlencoded::from_str::<Vec<(&str, Vec<Vec<bool>>)>>("a=b").is_err());
+    urlencoded::from_str::<Vec<(&str, Vec<Vec<bool>>)>>("a=b").unwrap_err();
 }
 
 #[test]