diff --git a/src/main/java/com/crypto/codec/Base64.java b/src/main/java/com/crypto/codec/Base64.java
index 9d1ff91c..f65faf96 100644
--- a/src/main/java/com/crypto/codec/Base64.java
+++ b/src/main/java/com/crypto/codec/Base64.java
@@ -184,7 +184,7 @@ public class Base64 {
 
         decodedBlock[0] = (byte) (decodeAlphabet[block[0]] << 2 | decodeAlphabet[block[1]] >>> 4);
         decodedBlock[1] = (byte) (decodeAlphabet[block[1]] << 4 | decodeAlphabet[block[2]] >>> 2);
-        decodedBlock[2] = (byte) (decodeAlphabet[block[2]] << 6 | decodeAlphabet[block[3]]);
+        decodedBlock[2] = (byte) (decodeAlphabet[block[2]] << 6 | decodeAlphabet[block[3]] & 0xff);
 
         return decodedBlock;
     }
diff --git a/src/main/java/com/generation/SimplexNoise.java b/src/main/java/com/generation/SimplexNoise.java
index a4fcb3f1..fb4473dc 100644
--- a/src/main/java/com/generation/SimplexNoise.java
+++ b/src/main/java/com/generation/SimplexNoise.java
@@ -36,7 +36,7 @@ public class SimplexNoise {
 
             this.octaves[index] = new SimplexNoiseOctave(random.nextInt());
             this.frequencys[index] = Math.pow(2, index);
-            this.amplitudes[index] = Math.pow(persistence, octaveCount - index);
+            this.amplitudes[index] = Math.pow(persistence, (double) octaveCount - index);
         }
     }
 
@@ -103,7 +103,7 @@ public class SimplexNoise {
         for (int index = 0; index < this.octaves.length; index++) {
 
             double frequency = Math.pow(2, index);
-            double amplitude = Math.pow(this.persistance, this.octaves.length - index);
+            double amplitude = Math.pow(this.persistance, (double) this.octaves.length - index);
 
             result += this.octaves[index].noise(x / frequency, y / frequency, z / frequency) * amplitude;
         }