diff --git a/fn/either_test.go b/fn/either_test.go
index dca15f8d9..81af2bc6c 100644
--- a/fn/either_test.go
+++ b/fn/either_test.go
@@ -100,16 +100,14 @@ func TestPropToOptionIdentities(t *testing.T) {
 			e = NewRight[int, string](s)
 
 			r2O := e.RightToOption() == Some(s)
-			o2R := e == OptionToRight[string, int, string](
-				Some(s), i,
-			)
+			o2R := e == OptionToRight(Some(s), i)
 			l2O := e.LeftToOption() == None[int]()
 
 			return r2O && o2R && l2O
 		} else {
 			e = NewLeft[int, string](i)
 			l2O := e.LeftToOption() == Some(i)
-			o2L := e == OptionToLeft[int, int](Some(i), s)
+			o2L := e == OptionToLeft(Some(i), s)
 			r2O := e.RightToOption() == None[string]()
 
 			return l2O && o2L && r2O
diff --git a/fn/fn.go b/fn/fn.go
index 147bf7daf..ea9190b7f 100644
--- a/fn/fn.go
+++ b/fn/fn.go
@@ -23,7 +23,7 @@ func Iden[A any](a A) A {
 // Const is a function that accepts an argument and returns a function that
 // always returns that value irrespective of the returned function's argument.
 // This is also quite useful in conjunction with higher order functions.
-func Const[A, B any](a A) func(B) A {
+func Const[B, A any](a A) func(B) A {
 	return func(_ B) A {
 		return a
 	}
diff --git a/fn/option.go b/fn/option.go
index 57245a9ba..656be264d 100644
--- a/fn/option.go
+++ b/fn/option.go
@@ -216,7 +216,7 @@ func (o Option[A]) UnsafeFromSome() A {
 
 // OptionToLeft can be used to convert an Option value into an Either, by
 // providing the Right value that should be used if the Option value is None.
-func OptionToLeft[O, L, R any](o Option[O], r R) Either[O, R] {
+func OptionToLeft[O, R any](o Option[O], r R) Either[O, R] {
 	if o.IsSome() {
 		return NewLeft[O, R](o.some)
 	}
@@ -226,7 +226,7 @@ func OptionToLeft[O, L, R any](o Option[O], r R) Either[O, R] {
 
 // OptionToRight can be used to convert an Option value into an Either, by
 // providing the Left value that should be used if the Option value is None.
-func OptionToRight[O, L, R any](o Option[O], l L) Either[L, O] {
+func OptionToRight[O, L any](o Option[O], l L) Either[L, O] {
 	if o.IsSome() {
 		return NewRight[L, O](o.some)
 	}
@@ -239,7 +239,7 @@ func OptionToRight[O, L, R any](o Option[O], l L) Either[L, O] {
 // and Some is converted to Ok.
 func (o Option[A]) SomeToOk(err error) Result[A] {
 	return Result[A]{
-		OptionToLeft[A, A, error](o, err),
+		OptionToLeft(o, err),
 	}
 }
 
@@ -248,7 +248,7 @@ func (o Option[A]) SomeToOk(err error) Result[A] {
 // ignored and Some is converted to Ok.
 func (o Option[A]) SomeToOkf(errString string, args ...interface{}) Result[A] {
 	return Result[A]{
-		OptionToLeft[A, A, error](o, fmt.Errorf(errString, args...)),
+		OptionToLeft(o, fmt.Errorf(errString, args...)),
 	}
 }
 
diff --git a/fn/slice_test.go b/fn/slice_test.go
index fae9bd361..18f7602ad 100644
--- a/fn/slice_test.go
+++ b/fn/slice_test.go
@@ -427,7 +427,7 @@ func TestSingletonInitIsEmpty(t *testing.T) {
 // empty slice.
 func TestPropAlwaysNoneEmptyFilterMap(t *testing.T) {
 	f := func(s []int) bool {
-		filtered := FilterMap(s, Const[Option[int], int](None[int]()))
+		filtered := FilterMap(s, Const[int](None[int]()))
 		return len(filtered) == 0
 	}