diff --git a/tests/source/trait.rs b/tests/source/trait.rs
index e04c71824214..5e7a0c78ba70 100644
--- a/tests/source/trait.rs
+++ b/tests/source/trait.rs
@@ -31,3 +31,7 @@ trait Runnable {
 trait TraitWithExpr {
     fn fn_with_expr(x: [i32;       1]);
 }
+
+trait Test {
+    fn read_struct<T, F>(&mut self, s_name: &str, len: usize, f: F) -> Result<T, Self::Error> where F: FnOnce(&mut Self) -> Result<T, Self::Error>;
+}
diff --git a/tests/target/trait.rs b/tests/target/trait.rs
index ffc5b87c6ea9..241f5d05b7c8 100644
--- a/tests/target/trait.rs
+++ b/tests/target/trait.rs
@@ -29,3 +29,8 @@ trait Runnable {
 trait TraitWithExpr {
     fn fn_with_expr(x: [i32; 1]);
 }
+
+trait Test {
+    fn read_struct<T, F>(&mut self, s_name: &str, len: usize, f: F) -> Result<T, Self::Error>
+        where F: FnOnce(&mut Self) -> Result<T, Self::Error>;
+}