diff --git a/tests/source/structs.rs b/tests/source/structs.rs
index 56471f1d7e42..d4ee741d4d34 100644
--- a/tests/source/structs.rs
+++ b/tests/source/structs.rs
@@ -281,3 +281,7 @@ struct Test {
     pub join: Vec<String>,
     #[serde(default)] pub tls: bool,
 }
+
+// #2818
+struct Paren((i32)) where i32: Trait;
+struct Parens((i32, i32)) where i32: Trait;
diff --git a/tests/target/structs.rs b/tests/target/structs.rs
index 368650bb6a88..829a4de53151 100644
--- a/tests/target/structs.rs
+++ b/tests/target/structs.rs
@@ -334,3 +334,11 @@ struct Test {
     #[serde(default)]
     pub tls: bool,
 }
+
+// #2818
+struct Paren((i32))
+where
+    i32: Trait;
+struct Parens((i32, i32))
+where
+    i32: Trait;