diff --git a/test/passing/tests/function_constraint.ml b/test/passing/tests/function_constraint.ml
index 30459ed817..cb62dbc9f1 100644
--- a/test/passing/tests/function_constraint.ml
+++ b/test/passing/tests/function_constraint.ml
@@ -1,19 +1,34 @@
-let f = fun (type a) -> (() : unit)
+(* RHS annotated with a type *)
+let f (type a) = (() : unit)
 
-let f = fun (type a : immediate) -> (() : unit)
+let f (type a : immediate) = (() : unit)
 
-let f = fun (type a) x -> (() : unit)
+let f x y = (() : unit)
 
-let f = fun x y -> (() : unit)
+(* RHS annotated with a type and mode *)
+let f (type a) = (() : unit @@ local)
 
-let f = fun (type a : value) x -> (() : unit)
+let f (type a : value) = (() : unit @@ local)
 
-let f = fun (type a) -> (() : unit @@ local)
+let f x y = (() : unit @@ local)
 
-let f = fun (type a : immediate) -> (() : unit @@ local)
+(* LHS and RHS annotated with the same type *)
+let f (type a) : unit = (() : unit)
 
-let f = fun (type a) x -> (() : unit @@ local)
+let f (type a : value) : unit = (() : unit)
 
-let f = fun x y -> (() : unit @@ local)
+let f x y : unit = (() : unit)
 
-let f = fun (type a : value) x -> (() : unit @@ local)
+(* LHS and RHS annotated with different types *)
+let f (type a) : unit = (() : int)
+
+let f (type a : value) : unit = (() : int)
+
+let f x y : unit = (() : int)
+
+(* LHS annotated with a mode, RHS annotated with a type *)
+let (f @ local) (type a) = (() : unit)
+
+let (f @ local) (type a : value) = (() : unit)
+
+let (f @ local) x y  = (() : unit)
diff --git a/test/passing/tests/function_constraint.ml.js-ref b/test/passing/tests/function_constraint.ml.js-ref
index aa3a05a598..08dde1fdbe 100644
--- a/test/passing/tests/function_constraint.ml.js-ref
+++ b/test/passing/tests/function_constraint.ml.js-ref
@@ -1,10 +1,24 @@
+(* RHS annotated with a type *)
 let f (type a) : unit = ()
 let f (type a : immediate) : unit = ()
-let f (type a) x : unit = ()
 let f x y : unit = ()
-let f (type a : value) x : unit = ()
+
+(* RHS annotated with a type and mode *)
 let f (type a) = (() : unit @@ local)
-let f (type a : immediate) = (() : unit @@ local)
-let f (type a) x = (() : unit @@ local)
+let f (type a : value) = (() : unit @@ local)
 let f x y = (() : unit @@ local)
-let f (type a : value) x = (() : unit @@ local)
+
+(* LHS and RHS annotated with the same type *)
+let f (type a) : unit = (() : unit)
+let f (type a : value) : unit = (() : unit)
+let f x y : unit = (() : unit)
+
+(* LHS and RHS annotated with different types *)
+let f (type a) : unit = (() : int)
+let f (type a : value) : unit = (() : int)
+let f x y : unit = (() : int)
+
+(* LHS annotated with a mode, RHS annotated with a type *)
+let (f @ local) (type a) : unit = ()
+let (f @ local) (type a : value) : unit = ()
+let (f @ local) x y : unit = ()
diff --git a/test/passing/tests/function_constraint.ml.ref b/test/passing/tests/function_constraint.ml.ref
index ee46d77d01..9bc3b33198 100644
--- a/test/passing/tests/function_constraint.ml.ref
+++ b/test/passing/tests/function_constraint.ml.ref
@@ -1,19 +1,34 @@
+(* RHS annotated with a type *)
 let f (type a) : unit = ()
 
 let f (type a : immediate) : unit = ()
 
-let f (type a) x : unit = ()
-
 let f x y : unit = ()
 
-let f (type a : value) x : unit = ()
-
+(* RHS annotated with a type and mode *)
 let f (type a) = (() : unit @@ local)
 
-let f (type a : immediate) = (() : unit @@ local)
-
-let f (type a) x = (() : unit @@ local)
+let f (type a : value) = (() : unit @@ local)
 
 let f x y = (() : unit @@ local)
 
-let f (type a : value) x = (() : unit @@ local)
+(* LHS and RHS annotated with the same type *)
+let f (type a) : unit = (() : unit)
+
+let f (type a : value) : unit = (() : unit)
+
+let f x y : unit = (() : unit)
+
+(* LHS and RHS annotated with different types *)
+let f (type a) : unit = (() : int)
+
+let f (type a : value) : unit = (() : int)
+
+let f x y : unit = (() : int)
+
+(* LHS annotated with a mode, RHS annotated with a type *)
+let (f @ local) (type a) : unit = ()
+
+let (f @ local) (type a : value) : unit = ()
+
+let (f @ local) x y : unit = ()