diff --git a/_tools/codegen_sobol/main.go b/_tools/codegen_sobol/main.go
index 12f2b9a6..dc549d16 100644
--- a/_tools/codegen_sobol/main.go
+++ b/_tools/codegen_sobol/main.go
@@ -103,7 +103,7 @@ func main() {
 	fmt.Fprintf(fout, "\n")
 	fmt.Fprintf(fout, "// The original data of direction numbers is distributed at https://web.maths.unsw.edu.au/~fkuo/sobol/ (BSD License).\n")
 	fmt.Fprintf(fout, "\n")
-	fmt.Fprintf(fout, "const maxDim = 21201 - 1002  // Due to skip 1000 lines\n")
+	fmt.Fprintf(fout, "const maxDim = 21201 - 2\n")
 	fmt.Fprintf(fout, "const maxDeg = 18\n")
 	fmt.Fprintf(fout, "const maxBit = 30\n")
 	fmt.Fprintf(fout, "\n")
diff --git a/sobol/direction_numbers.go b/sobol/direction_numbers.go
index 4a0ca922..c3adb1e3 100644
--- a/sobol/direction_numbers.go
+++ b/sobol/direction_numbers.go
@@ -4,7 +4,7 @@ package sobol
 
 // The original data of direction numbers is distributed at https://web.maths.unsw.edu.au/~fkuo/sobol/ (BSD License).
 
-const maxDim = 21201 - 1002  // Due to skip 1000 lines
+const maxDim = 21201 - 2
 const maxDeg = 18
 const maxBit = 30
 
diff --git a/sobol/engine.go b/sobol/engine.go
index 4677089f..65fb8003 100644
--- a/sobol/engine.go
+++ b/sobol/engine.go
@@ -30,10 +30,13 @@ func initDirectionNumbers(dim uint32) [][]uint32 {
 		v[j] = make([]uint32, maxBit+1)
 
 		// Read in parameters from file
-		// Skip 1000 lines from the top as Joe&Kuo's C++ program do.
-		dn := directionNumbers[1000+j]
+		dn := directionNumbers[j]
+		m := make([]uint32, len(dn.M)+1)
+		for i := uint32(0); i < dn.S; i++ {
+			m[i+1] = dn.M[i]
+		}
 		for i := uint32(1); i <= dn.S; i++ {
-			v[j][i] = dn.M[i-1] << (32 - i)
+			v[j][i] = m[i] << (32 - i)
 		}
 		for i := dn.S + 1; i <= maxBit; i++ {
 			v[j][i] = v[j][i-dn.S] ^ (v[j][i-dn.S] >> dn.S)