diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..f64ee3b
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,9 @@
+# Visual Studio 2015/2017 cache/options directory
+.vs/
+
+# Build results
+[Dd]ebug/
+[Rr]elease/
+x64/
+[Bb]in/
+[Oo]bj/
diff --git a/SimplexNoise/Noise.cs b/SimplexNoise/Noise.cs
index 25a5090..fe9ebba 100644
--- a/SimplexNoise/Noise.cs
+++ b/SimplexNoise/Noise.cs
@@ -120,9 +120,14 @@ public static int Seed
                 }
                 else
                 {
+                    // permutation matrix is duplicated to handle rollovers
                     _perm = new byte[512];
-                    var random = new Random(value);
-                    random.NextBytes(_perm);
+
+                    var perm = new byte[256];
+                    new Random(value).NextBytes(perm);
+
+                    Array.Copy(perm, 0, _perm, 0, 256);
+                    Array.Copy(perm, 0, _perm, 256, 256);
                 }
 
                 _seed = value;