diff --git a/ffi/go/mcl/mcl.go b/ffi/go/mcl/mcl.go
index 97f0c7d..1dd9b84 100644
--- a/ffi/go/mcl/mcl.go
+++ b/ffi/go/mcl/mcl.go
@@ -31,6 +31,9 @@ const IO_EC_AFFINE = C.MCLBN_IO_EC_AFFINE
 // IO_EC_PROJ --
 const IO_EC_PROJ = C.MCLBN_IO_EC_PROJ
 
+// IRTF -- for SetMapToMode
+const IRTF = 5 /* MCL_MAP_TO_MODE_HASH_TO_CURVE_07 */
+
 // GetFrUnitSize --
 func GetFrUnitSize() int {
 	return int(C.MCLBN_FR_UNIT_SIZE)
@@ -170,8 +173,8 @@ func (x *Fr) SetString(s string, base int) error {
 // Deserialize --
 func (x *Fr) Deserialize(buf []byte) error {
 	// #nosec
-	err := C.mclBnFr_deserialize(x.getPointer(), unsafe.Pointer(&buf[0]), C.size_t(len(buf)))
-	if err == 0 {
+	n := C.mclBnFr_deserialize(x.getPointer(), unsafe.Pointer(&buf[0]), C.size_t(len(buf)))
+	if n == 0 || int(n) != len(buf) {
 		return fmt.Errorf("err mclBnFr_deserialize %x", buf)
 	}
 	return nil
@@ -197,6 +200,16 @@ func (x *Fr) SetLittleEndianMod(buf []byte) error {
 	return nil
 }
 
+// SetBigEndianMod --
+func (x *Fr) SetBigEndianMod(buf []byte) error {
+	// #nosec
+	err := C.mclBnFr_setBigEndianMod(x.getPointer(), unsafe.Pointer(&buf[0]), C.size_t(len(buf)))
+	if err != 0 {
+		return fmt.Errorf("err mclBnFr_setBigEndianMod %x", err)
+	}
+	return nil
+}
+
 // IsEqual --
 func (x *Fr) IsEqual(rhs *Fr) bool {
 	return C.mclBnFr_isEqual(x.getPointer(), rhs.getPointer()) == 1
@@ -340,8 +353,8 @@ func (x *Fp) SetString(s string, base int) error {
 // Deserialize --
 func (x *Fp) Deserialize(buf []byte) error {
 	// #nosec
-	err := C.mclBnFp_deserialize(x.getPointer(), unsafe.Pointer(&buf[0]), C.size_t(len(buf)))
-	if err == 0 {
+	n := C.mclBnFp_deserialize(x.getPointer(), unsafe.Pointer(&buf[0]), C.size_t(len(buf)))
+	if n == 0 || int(n) != len(buf) {
 		return fmt.Errorf("err mclBnFp_deserialize %x", buf)
 	}
 	return nil
@@ -367,6 +380,16 @@ func (x *Fp) SetLittleEndianMod(buf []byte) error {
 	return nil
 }
 
+// SetBigEndianMod --
+func (x *Fp) SetBigEndianMod(buf []byte) error {
+	// #nosec
+	err := C.mclBnFp_setBigEndianMod(x.getPointer(), unsafe.Pointer(&buf[0]), C.size_t(len(buf)))
+	if err != 0 {
+		return fmt.Errorf("err mclBnFp_setBigEndianMod %x", err)
+	}
+	return nil
+}
+
 // IsEqual --
 func (x *Fp) IsEqual(rhs *Fp) bool {
 	return C.mclBnFp_isEqual(x.getPointer(), rhs.getPointer()) == 1
@@ -493,8 +516,8 @@ func (x *Fp2) Clear() {
 // Deserialize --
 func (x *Fp2) Deserialize(buf []byte) error {
 	// #nosec
-	err := C.mclBnFp2_deserialize(x.getPointer(), unsafe.Pointer(&buf[0]), C.size_t(len(buf)))
-	if err == 0 {
+	n := C.mclBnFp2_deserialize(x.getPointer(), unsafe.Pointer(&buf[0]), C.size_t(len(buf)))
+	if n == 0 || int(n) != len(buf) {
 		return fmt.Errorf("err mclBnFp2_deserialize %x", buf)
 	}
 	return nil
@@ -599,8 +622,8 @@ func (x *G1) SetString(s string, base int) error {
 // Deserialize --
 func (x *G1) Deserialize(buf []byte) error {
 	// #nosec
-	err := C.mclBnG1_deserialize(x.getPointer(), unsafe.Pointer(&buf[0]), C.size_t(len(buf)))
-	if err == 0 {
+	n := C.mclBnG1_deserialize(x.getPointer(), unsafe.Pointer(&buf[0]), C.size_t(len(buf)))
+	if n == 0 || int(n) != len(buf) {
 		return fmt.Errorf("err mclBnG1_deserialize %x", buf)
 	}
 	return nil
@@ -796,8 +819,8 @@ func (x *G2) SetString(s string, base int) error {
 // Deserialize --
 func (x *G2) Deserialize(buf []byte) error {
 	// #nosec
-	err := C.mclBnG2_deserialize(x.getPointer(), unsafe.Pointer(&buf[0]), C.size_t(len(buf)))
-	if err == 0 {
+	n := C.mclBnG2_deserialize(x.getPointer(), unsafe.Pointer(&buf[0]), C.size_t(len(buf)))
+	if n == 0 || int(n) != len(buf) {
 		return fmt.Errorf("err mclBnG2_deserialize %x", buf)
 	}
 	return nil
@@ -976,8 +999,8 @@ func (x *GT) SetString(s string, base int) error {
 // Deserialize --
 func (x *GT) Deserialize(buf []byte) error {
 	// #nosec
-	err := C.mclBnGT_deserialize(x.getPointer(), unsafe.Pointer(&buf[0]), C.size_t(len(buf)))
-	if err == 0 {
+	n := C.mclBnGT_deserialize(x.getPointer(), unsafe.Pointer(&buf[0]), C.size_t(len(buf)))
+	if n == 0 || int(n) != len(buf) {
 		return fmt.Errorf("err mclBnGT_deserialize %x", buf)
 	}
 	return nil
diff --git a/ffi/go/mcl/mcl_test.go b/ffi/go/mcl/mcl_test.go
index e128648..a182aca 100644
--- a/ffi/go/mcl/mcl_test.go
+++ b/ffi/go/mcl/mcl_test.go
@@ -2,6 +2,7 @@ package mcl
 
 import "testing"
 import "fmt"
+import "encoding/hex"
 
 func testBadPointOfG2(t *testing.T) {
 	var Q G2
@@ -261,6 +262,29 @@ func testETHserialize(t *testing.T) {
 	fmt.Printf("AAA x=%s\n", x.GetString(16))
 }
 
+func testMapToG1(t *testing.T) {
+	SetMapToMode(IRTF)
+	fpHex := "0000000000000000000000000000000014406e5bfb9209256a3820879a29ac2f62d6aca82324bf3ae2aa7d3c54792043bd8c791fccdb080c1a52dc68b8b69350"
+	g1Hex := "ad7721bcdb7ce1047557776eb2659a444166dc6dd55c7ca6e240e21ae9aa18f529f04ac31d861b54faf3307692545db7"
+	fpBin, _ := hex.DecodeString(fpHex)
+	var x Fp
+	x.SetBigEndianMod(fpBin)
+	var P1 G1
+	err := MapToG1(&P1, &x)
+	if err != nil {
+		t.Fatal("MapToG1")
+	}
+	g1Str, _ := hex.DecodeString(g1Hex)
+	var P2 G1
+	err = P2.Deserialize(g1Str)
+	if err != nil {
+		t.Fatal("G1.Deserialize")
+	}
+	if !P1.IsEqual(&P2) {
+		t.Fatal("bad MapToG1")
+	}
+}
+
 func TestMclMain(t *testing.T) {
 	t.Logf("GetMaxOpUnitSize() = %d\n", GetMaxOpUnitSize())
 	t.Log("CurveFp254BNb")
@@ -273,5 +297,6 @@ func TestMclMain(t *testing.T) {
 		t.Log("BLS12_381")
 		testMcl(t, BLS12_381)
 		testETHserialize(t)
+		testMapToG1(t)
 	}
 }