diff --git a/builtin/v10/util/math/ln.go b/builtin/v10/util/math/ln.go
index 4d21b23b..cd54c7e6 100644
--- a/builtin/v10/util/math/ln.go
+++ b/builtin/v10/util/math/ln.go
@@ -51,7 +51,7 @@ func init() {
 func Ln(z big.Int) big.Int {
 	// bitlen - 1 - precision
 	k := int64(z.BitLen()) - 1 - Precision128 // Q.0
-	x := big.Zero()                           // nolint:ineffassign
+	var x big.Int
 
 	if k > 0 {
 		x = big.Rsh(z, uint(k)) // Q.128
diff --git a/builtin/v11/util/math/ln.go b/builtin/v11/util/math/ln.go
index 4d21b23b..cd54c7e6 100644
--- a/builtin/v11/util/math/ln.go
+++ b/builtin/v11/util/math/ln.go
@@ -51,7 +51,7 @@ func init() {
 func Ln(z big.Int) big.Int {
 	// bitlen - 1 - precision
 	k := int64(z.BitLen()) - 1 - Precision128 // Q.0
-	x := big.Zero()                           // nolint:ineffassign
+	var x big.Int
 
 	if k > 0 {
 		x = big.Rsh(z, uint(k)) // Q.128
diff --git a/builtin/v12/util/math/ln.go b/builtin/v12/util/math/ln.go
index 4d21b23b..cd54c7e6 100644
--- a/builtin/v12/util/math/ln.go
+++ b/builtin/v12/util/math/ln.go
@@ -51,7 +51,7 @@ func init() {
 func Ln(z big.Int) big.Int {
 	// bitlen - 1 - precision
 	k := int64(z.BitLen()) - 1 - Precision128 // Q.0
-	x := big.Zero()                           // nolint:ineffassign
+	var x big.Int
 
 	if k > 0 {
 		x = big.Rsh(z, uint(k)) // Q.128
diff --git a/builtin/v13/util/math/ln.go b/builtin/v13/util/math/ln.go
index 4d21b23b..cd54c7e6 100644
--- a/builtin/v13/util/math/ln.go
+++ b/builtin/v13/util/math/ln.go
@@ -51,7 +51,7 @@ func init() {
 func Ln(z big.Int) big.Int {
 	// bitlen - 1 - precision
 	k := int64(z.BitLen()) - 1 - Precision128 // Q.0
-	x := big.Zero()                           // nolint:ineffassign
+	var x big.Int
 
 	if k > 0 {
 		x = big.Rsh(z, uint(k)) // Q.128