diff --git a/internal/sm2ec/sm2p256.go b/internal/sm2ec/sm2p256.go
index 122e207..cbd5638 100644
--- a/internal/sm2ec/sm2p256.go
+++ b/internal/sm2ec/sm2p256.go
@@ -322,9 +322,9 @@ func (table *sm2p256Table) Select(p *SM2P256Point, n uint8) {
 		panic("sm2ec: internal error: sm2p256Table called with out-of-bounds value")
 	}
 	p.Set(NewSM2P256Point())
-	for i := uint8(1); i < 16; i++ {
-		cond := subtle.ConstantTimeByteEq(i, n)
-		p.Select(table[i-1], p, cond)
+	for i, f := range table {
+		cond := subtle.ConstantTimeByteEq(uint8(i+1), n)
+		p.Select(f, p, cond)
 	}
 }
 
diff --git a/sm9/bn256/curve.go b/sm9/bn256/curve.go
index c16aef8..46382b4 100644
--- a/sm9/bn256/curve.go
+++ b/sm9/bn256/curve.go
@@ -270,8 +270,8 @@ func (table *curvePointTable) Select(p *curvePoint, n uint8) {
 		panic("sm9: internal error: curvePointTable called with out-of-bounds value")
 	}
 	p.SetInfinity()
-	for i := uint8(1); i < 16; i++ {
-		cond := subtle.ConstantTimeByteEq(i, n)
-		p.Select(table[i-1], p, cond)
+	for i, f := range table {
+		cond := subtle.ConstantTimeByteEq(uint8(i+1), n)
+		p.Select(f, p, cond)
 	}
 }
diff --git a/sm9/bn256/gfp_generic.go b/sm9/bn256/gfp_generic.go
index 58505da..e8b7451 100644
--- a/sm9/bn256/gfp_generic.go
+++ b/sm9/bn256/gfp_generic.go
@@ -30,7 +30,7 @@ func gfpNeg(c, a *gfP) {
 	for i, pi := range p2 {
 		c[i], carry = bits.Sub64(pi, a[i], carry)
 	}
-	// required for "zero", bn256 treat infinity point as valid
+	// required for "zero", bn256 treats infinity point as valid
 	gfpCarry(c, 0)
 }
 
diff --git a/sm9/bn256/gt.go b/sm9/bn256/gt.go
index 004acbe..bf46060 100644
--- a/sm9/bn256/gt.go
+++ b/sm9/bn256/gt.go
@@ -211,9 +211,9 @@ func (table *GTFieldTable) Select(p *GT, n uint8) {
 		panic("sm9: internal error: GTFieldTable called with out-of-bounds value")
 	}
 	p.p.SetOne()
-	for i := uint8(1); i < 16; i++ {
-		cond := subtle.ConstantTimeByteEq(i, n)
-		p.p.Select(table[i-1].p, p.p, cond)
+	for i, f := range table {
+		cond := subtle.ConstantTimeByteEq(uint8(i+1), n)
+		p.p.Select(f.p, p.p, cond)
 	}
 }
 
diff --git a/sm9/bn256/twist.go b/sm9/bn256/twist.go
index c42eb16..b5cb9f7 100644
--- a/sm9/bn256/twist.go
+++ b/sm9/bn256/twist.go
@@ -262,9 +262,9 @@ func (table *twistPointTable) Select(p *twistPoint, n uint8) {
 		panic("sm9: internal error: twistPointTable called with out-of-bounds value")
 	}
 	p.SetInfinity()
-	for i := uint8(1); i < 16; i++ {
-		cond := subtle.ConstantTimeByteEq(i, n)
-		p.Select(table[i-1], p, cond)
+	for i, f := range table {
+		cond := subtle.ConstantTimeByteEq(uint8(i+1), n)
+		p.Select(f, p, cond)
 	}
 }