diff --git a/lib/src/main/java/com/auth0/jwt/JWTCreator.java b/lib/src/main/java/com/auth0/jwt/JWTCreator.java
index f5b70c13..526a9000 100644
--- a/lib/src/main/java/com/auth0/jwt/JWTCreator.java
+++ b/lib/src/main/java/com/auth0/jwt/JWTCreator.java
@@ -11,12 +11,13 @@
 import com.fasterxml.jackson.databind.module.SimpleModule;
 import org.apache.commons.codec.binary.Base64;
 
+import java.nio.charset.StandardCharsets;
 import java.util.Date;
 import java.util.HashMap;
 import java.util.Map;
 
 /**
- * The JWTCreator class holds the sign method to generate a complete DecodedJWT (with Signature) from a given Header and Payload content.
+ * The JWTCreator class holds the sign method to generate a complete JWT (with Signature) from a given Header and Payload content.
  */
 @SuppressWarnings("WeakerAccess")
 public final class JWTCreator {
@@ -50,7 +51,7 @@ static JWTCreator.Builder init() {
     }
 
     /**
-     * The Builder class holds the Claims that defines the DecodedJWT to be created.
+     * The Builder class holds the Claims that defines the JWT to be created.
      */
     public static class Builder {
         private final Map<String, Object> payloadClaims;
@@ -139,7 +140,7 @@ public Builder withIssuedAt(Date issuedAt) {
         }
 
         /**
-         * Add a specific DecodedJWT Id ("jti") claim.
+         * Add a specific JWT Id ("jti") claim.
          *
          * @param jwtId the Token Id value.
          * @return this same Builder instance.
@@ -172,12 +173,12 @@ public Builder withClaim(String name, Object value) throws IllegalArgumentExcept
         }
 
         /**
-         * Creates a new instance of the DecodedJWT with the specified payloadClaims.
+         * Creates a new JWT and signs is with the given algorithm
          *
-         * @param algorithm the Algorithm to use on the DecodedJWT signing.
-         * @return a new DecodedJWT instance.
+         * @param algorithm used to sign the JWT
+         * @return a new JWT token
          * @throws IllegalArgumentException if the provided algorithm is null.
-         * @throws JWTCreationException     if the Claims coudln't be converted to a valid JSON or there was a problem with the signing key.
+         * @throws JWTCreationException     if the claims could not be converted to a valid JSON or there was a problem with the signing key.
          */
         public String sign(Algorithm algorithm) throws IllegalArgumentException, JWTCreationException {
             if (algorithm == null) {
@@ -197,11 +198,11 @@ private void addClaim(String name, Object value) {
     }
 
     private String sign() throws SignatureGenerationException {
-        String header = Base64.encodeBase64URLSafeString((headerJson.getBytes()));
-        String payload = Base64.encodeBase64URLSafeString((payloadJson.getBytes()));
+        String header = Base64.encodeBase64URLSafeString((headerJson.getBytes(StandardCharsets.UTF_8)));
+        String payload = Base64.encodeBase64URLSafeString((payloadJson.getBytes(StandardCharsets.UTF_8)));
         String content = String.format("%s.%s", header, payload);
 
-        byte[] signatureBytes = algorithm.sign(content.getBytes());
+        byte[] signatureBytes = algorithm.sign(content.getBytes(StandardCharsets.UTF_8));
         String signature = Base64.encodeBase64URLSafeString((signatureBytes));
 
         return String.format("%s.%s", content, signature);
diff --git a/lib/src/main/java/com/auth0/jwt/JWTDecoder.java b/lib/src/main/java/com/auth0/jwt/JWTDecoder.java
index 0c080375..1c0c0afc 100644
--- a/lib/src/main/java/com/auth0/jwt/JWTDecoder.java
+++ b/lib/src/main/java/com/auth0/jwt/JWTDecoder.java
@@ -13,7 +13,7 @@
 import java.util.List;
 
 /**
- * The JWTDecoder class holds the decode method to parse a given Token into it's DecodedJWT representation.
+ * The JWTDecoder class holds the decode method to parse a given JWT token into it's JWT representation.
  */
 @SuppressWarnings("WeakerAccess")
 final class JWTDecoder extends JWT {
diff --git a/lib/src/main/java/com/auth0/jwt/JWTVerifier.java b/lib/src/main/java/com/auth0/jwt/JWTVerifier.java
index d0d2905c..b9077cb2 100644
--- a/lib/src/main/java/com/auth0/jwt/JWTVerifier.java
+++ b/lib/src/main/java/com/auth0/jwt/JWTVerifier.java
@@ -10,10 +10,11 @@
 import com.auth0.jwt.interfaces.DecodedJWT;
 import org.apache.commons.codec.binary.Base64;
 
+import java.nio.charset.StandardCharsets;
 import java.util.*;
 
 /**
- * The JWTVerifier class holds the verify method to assert that a given Token has not only a proper DecodedJWT format, but also it's signature matches.
+ * The JWTVerifier class holds the verify method to assert that a given Token has not only a proper JWT format, but also it's signature matches.
  */
 @SuppressWarnings("WeakerAccess")
 public final class JWTVerifier {
@@ -30,7 +31,7 @@ public final class JWTVerifier {
     /**
      * Initialize a JWTVerifier instance using the given Algorithm.
      *
-     * @param algorithm the Algorithm to use on the DecodedJWT verification.
+     * @param algorithm the Algorithm to use on the JWT verification.
      * @return a JWTVerifier.Verification instance to configure.
      * @throws IllegalArgumentException if the provided algorithm is null.
      */
@@ -39,7 +40,7 @@ static JWTVerifier.Verification init(Algorithm algorithm) throws IllegalArgument
     }
 
     /**
-     * The Verification class holds the Claims required by a DecodedJWT to be valid.
+     * The Verification class holds the Claims required by a JWT to be valid.
      */
     public static class Verification {
         private final Algorithm algorithm;
@@ -154,7 +155,7 @@ public Verification acceptIssuedAt(long leeway) throws IllegalArgumentException
         }
 
         /**
-         * Require a specific DecodedJWT Id ("jti") claim.
+         * Require a specific JWT Id ("jti") claim.
          *
          * @param jwtId the required Id value
          * @return this same Verification instance.
@@ -232,9 +233,9 @@ private void requireClaim(String name, Object value) {
     /**
      * Perform the verification against the given Token, using any previous configured options.
      *
-     * @param token the String representation of the DecodedJWT.
-     * @return a verified DecodedJWT.
-     * @throws JWTVerificationException if any of the required contents inside the DecodedJWT is invalid.
+     * @param token to verify.
+     * @return a verified and decoded JWT.
+     * @throws JWTVerificationException if any of the required contents inside the JWT is invalid.
      */
     public DecodedJWT verify(String token) throws JWTVerificationException {
         DecodedJWT jwt = JWTDecoder.decode(token);
@@ -245,14 +246,14 @@ public DecodedJWT verify(String token) throws JWTVerificationException {
     }
 
     private void verifySignature(String[] parts) throws SignatureVerificationException {
-        byte[] content = String.format("%s.%s", parts[0], parts[1]).getBytes();
+        byte[] content = String.format("%s.%s", parts[0], parts[1]).getBytes(StandardCharsets.UTF_8);
         byte[] signature = Base64.decodeBase64(parts[2]);
         algorithm.verify(content, signature);
     }
 
     private void verifyAlgorithm(DecodedJWT jwt, Algorithm expectedAlgorithm) throws AlgorithmMismatchException {
         if (!expectedAlgorithm.getName().equals(jwt.getAlgorithm())) {
-            throw new AlgorithmMismatchException("The provided Algorithm doesn't match the one defined in the DecodedJWT's Header.");
+            throw new AlgorithmMismatchException("The provided Algorithm doesn't match the one defined in the JWT's Header.");
         }
     }
 
diff --git a/lib/src/main/java/com/auth0/jwt/algorithms/Algorithm.java b/lib/src/main/java/com/auth0/jwt/algorithms/Algorithm.java
index e00bed16..b74b1aa3 100644
--- a/lib/src/main/java/com/auth0/jwt/algorithms/Algorithm.java
+++ b/lib/src/main/java/com/auth0/jwt/algorithms/Algorithm.java
@@ -160,7 +160,7 @@ protected Algorithm(String name, String description) {
     }
 
     /**
-     * Getter for the name of this Algorithm, as defined in the DecodedJWT Standard. i.e. "HS256"
+     * Getter for the name of this Algorithm, as defined in the JWT Standard. i.e. "HS256"
      *
      * @return the algorithm name.
      */
diff --git a/lib/src/main/java/com/auth0/jwt/interfaces/DecodedJWT.java b/lib/src/main/java/com/auth0/jwt/interfaces/DecodedJWT.java
index 651a9baa..b672b474 100644
--- a/lib/src/main/java/com/auth0/jwt/interfaces/DecodedJWT.java
+++ b/lib/src/main/java/com/auth0/jwt/interfaces/DecodedJWT.java
@@ -1,7 +1,7 @@
 package com.auth0.jwt.interfaces;
 
 /**
- * The DecodedJWT class represents a Json Web Token.
+ * Class that represents a Json Web Token that was decoded from it's string representation.
  */
 public interface DecodedJWT extends Payload, Header, Signature {
     String getToken();
diff --git a/lib/src/main/java/com/auth0/jwt/interfaces/Header.java b/lib/src/main/java/com/auth0/jwt/interfaces/Header.java
index b656c89b..2af99788 100644
--- a/lib/src/main/java/com/auth0/jwt/interfaces/Header.java
+++ b/lib/src/main/java/com/auth0/jwt/interfaces/Header.java
@@ -1,26 +1,26 @@
 package com.auth0.jwt.interfaces;
 
 /**
- * The Header class represents the 1st part of the DecodedJWT, where the Header value is hold.
+ * The Header class represents the 1st part of the JWT, where the Header value is hold.
  */
 public interface Header {
 
     /**
-     * Getter for the Algorithm "alg" claim defined in the DecodedJWT's Header. If the claim is missing it will return null.
+     * Getter for the Algorithm "alg" claim defined in the JWT's Header. If the claim is missing it will return null.
      *
      * @return the Algorithm defined or null.
      */
     String getAlgorithm();
 
     /**
-     * Getter for the Type "typ" claim defined in the DecodedJWT's Header. If the claim is missing it will return null.
+     * Getter for the Type "typ" claim defined in the JWT's Header. If the claim is missing it will return null.
      *
      * @return the Type defined or null.
      */
     String getType();
 
     /**
-     * Getter for the Content Type "cty" claim defined in the DecodedJWT's Header. If the claim is missing it will return null.
+     * Getter for the Content Type "cty" claim defined in the JWT's Header. If the claim is missing it will return null.
      *
      * @return the Content Type defined or null.
      */
diff --git a/lib/src/main/java/com/auth0/jwt/interfaces/JWTPartsParser.java b/lib/src/main/java/com/auth0/jwt/interfaces/JWTPartsParser.java
index 99300530..520e35c8 100644
--- a/lib/src/main/java/com/auth0/jwt/interfaces/JWTPartsParser.java
+++ b/lib/src/main/java/com/auth0/jwt/interfaces/JWTPartsParser.java
@@ -3,7 +3,7 @@
 import com.auth0.jwt.exceptions.JWTDecodeException;
 
 /**
- * The JWTPartsParser class defines which parts of the DecodedJWT should be converted to it's specific Object representation instance.
+ * The JWTPartsParser class defines which parts of the JWT should be converted to it's specific Object representation instance.
  */
 public interface JWTPartsParser {
 
diff --git a/lib/src/main/java/com/auth0/jwt/interfaces/Payload.java b/lib/src/main/java/com/auth0/jwt/interfaces/Payload.java
index 662e2cdc..2fd93cc2 100644
--- a/lib/src/main/java/com/auth0/jwt/interfaces/Payload.java
+++ b/lib/src/main/java/com/auth0/jwt/interfaces/Payload.java
@@ -4,7 +4,7 @@
 import java.util.List;
 
 /**
- * The Payload class represents the 2nd part of the DecodedJWT, where the Payload value is hold.
+ * The Payload class represents the 2nd part of the JWT, where the Payload value is hold.
  */
 public interface Payload {
 
@@ -53,7 +53,7 @@ public interface Payload {
     /**
      * Get the value of the "jti" claim, or null if it's not available.
      *
-     * @return the DecodedJWT ID value or null.
+     * @return the JWT ID value or null.
      */
     String getId();
 
diff --git a/lib/src/main/java/com/auth0/jwt/interfaces/Signature.java b/lib/src/main/java/com/auth0/jwt/interfaces/Signature.java
index d984e953..ae190bf3 100644
--- a/lib/src/main/java/com/auth0/jwt/interfaces/Signature.java
+++ b/lib/src/main/java/com/auth0/jwt/interfaces/Signature.java
@@ -1,14 +1,14 @@
 package com.auth0.jwt.interfaces;
 
 /**
- * The Signature class represents the 3rd part of the DecodedJWT, where the Signature value is hold.
+ * The Signature class represents the 3rd part of the JWT, where the Signature value is hold.
  */
 public interface Signature {
 
     /**
-     * Getter for the Signature contained in the DecodedJWT as a Base64 encoded String.
+     * Getter for the Signature contained in the JWT as a Base64 encoded String.
      *
-     * @return the Signature of the DecodedJWT.
+     * @return the Signature of the JWT.
      */
     String getSignature();
 }
diff --git a/lib/src/test/java/com/auth0/jwt/JWTDecoderTest.java b/lib/src/test/java/com/auth0/jwt/JWTDecoderTest.java
index ddacb0ab..b3e74f6e 100644
--- a/lib/src/test/java/com/auth0/jwt/JWTDecoderTest.java
+++ b/lib/src/test/java/com/auth0/jwt/JWTDecoderTest.java
@@ -11,6 +11,7 @@
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
 
+import java.nio.charset.StandardCharsets;
 import java.util.Date;
 
 import static org.hamcrest.MatcherAssert.assertThat;
@@ -200,8 +201,8 @@ public void shouldGetNullClaimIfClaimValueIsNull() throws Exception {
     //Helper Methods
 
     private DecodedJWT customJWT(String jsonHeader, String jsonPayload, String signature) {
-        String header = Base64.encodeBase64URLSafeString(jsonHeader.getBytes());
-        String body = Base64.encodeBase64URLSafeString(jsonPayload.getBytes());
+        String header = Base64.encodeBase64URLSafeString(jsonHeader.getBytes(StandardCharsets.UTF_8));
+        String body = Base64.encodeBase64URLSafeString(jsonPayload.getBytes(StandardCharsets.UTF_8));
         return JWTDecoder.decode(String.format("%s.%s.%s", header, body, signature));
     }
 
diff --git a/lib/src/test/java/com/auth0/jwt/JWTVerifierTest.java b/lib/src/test/java/com/auth0/jwt/JWTVerifierTest.java
index 004691e8..fe7b1cf5 100644
--- a/lib/src/test/java/com/auth0/jwt/JWTVerifierTest.java
+++ b/lib/src/test/java/com/auth0/jwt/JWTVerifierTest.java
@@ -33,7 +33,7 @@ public void shouldThrowWhenInitializedWithoutAlgorithm() throws Exception {
     @Test
     public void shouldThrowWhenAlgorithmDoesntMatchTheTokensAlgorithm() throws Exception {
         exception.expect(AlgorithmMismatchException.class);
-        exception.expectMessage("The provided Algorithm doesn't match the one defined in the DecodedJWT's Header.");
+        exception.expectMessage("The provided Algorithm doesn't match the one defined in the JWT's Header.");
         JWTVerifier verifier = JWTVerifier.init(Algorithm.HMAC512("secret")).build();
         verifier.verify("eyJhbGciOiJIUzI1NiJ9.eyJpc3MiOiJhdXRoMCJ9.s69x7Mmu4JqwmdxiK6sesALO7tcedbFsKEEITUxw9ho");
     }
diff --git a/lib/src/test/java/com/auth0/jwt/algorithms/AlgorithmTest.java b/lib/src/test/java/com/auth0/jwt/algorithms/AlgorithmTest.java
index c52ff64a..73b23dbb 100644
--- a/lib/src/test/java/com/auth0/jwt/algorithms/AlgorithmTest.java
+++ b/lib/src/test/java/com/auth0/jwt/algorithms/AlgorithmTest.java
@@ -4,6 +4,7 @@
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
 
+import java.nio.charset.StandardCharsets;
 import java.security.interfaces.ECKey;
 import java.security.interfaces.RSAKey;
 
@@ -109,35 +110,35 @@ public void shouldThrowECDSA512VerificationWithNullPublicKey() throws Exception
 
     @Test
     public void shouldCreateHMAC256AlgorithmWithBytes() throws Exception {
-        Algorithm algorithm = Algorithm.HMAC256("secret".getBytes());
+        Algorithm algorithm = Algorithm.HMAC256("secret".getBytes(StandardCharsets.UTF_8));
 
         assertThat(algorithm, is(notNullValue()));
         assertThat(algorithm, is(instanceOf(HMACAlgorithm.class)));
         assertThat(algorithm.getDescription(), is("HmacSHA256"));
         assertThat(algorithm.getName(), is("HS256"));
-        assertThat(((HMACAlgorithm) algorithm).getSecret(), is("secret".getBytes()));
+        assertThat(((HMACAlgorithm) algorithm).getSecret(), is("secret".getBytes(StandardCharsets.UTF_8)));
     }
 
     @Test
     public void shouldCreateHMAC384AlgorithmWithBytes() throws Exception {
-        Algorithm algorithm = Algorithm.HMAC384("secret".getBytes());
+        Algorithm algorithm = Algorithm.HMAC384("secret".getBytes(StandardCharsets.UTF_8));
 
         assertThat(algorithm, is(notNullValue()));
         assertThat(algorithm, is(instanceOf(HMACAlgorithm.class)));
         assertThat(algorithm.getDescription(), is("HmacSHA384"));
         assertThat(algorithm.getName(), is("HS384"));
-        assertThat(((HMACAlgorithm) algorithm).getSecret(), is("secret".getBytes()));
+        assertThat(((HMACAlgorithm) algorithm).getSecret(), is("secret".getBytes(StandardCharsets.UTF_8)));
     }
 
     @Test
     public void shouldCreateHMAC512AlgorithmWithBytes() throws Exception {
-        Algorithm algorithm = Algorithm.HMAC512("secret".getBytes());
+        Algorithm algorithm = Algorithm.HMAC512("secret".getBytes(StandardCharsets.UTF_8));
 
         assertThat(algorithm, is(notNullValue()));
         assertThat(algorithm, is(instanceOf(HMACAlgorithm.class)));
         assertThat(algorithm.getDescription(), is("HmacSHA512"));
         assertThat(algorithm.getName(), is("HS512"));
-        assertThat(((HMACAlgorithm) algorithm).getSecret(), is("secret".getBytes()));
+        assertThat(((HMACAlgorithm) algorithm).getSecret(), is("secret".getBytes(StandardCharsets.UTF_8)));
     }
 
     @Test
@@ -148,7 +149,7 @@ public void shouldCreateHMAC256AlgorithmWithString() throws Exception {
         assertThat(algorithm, is(instanceOf(HMACAlgorithm.class)));
         assertThat(algorithm.getDescription(), is("HmacSHA256"));
         assertThat(algorithm.getName(), is("HS256"));
-        assertThat(((HMACAlgorithm) algorithm).getSecret(), is("secret".getBytes()));
+        assertThat(((HMACAlgorithm) algorithm).getSecret(), is("secret".getBytes(StandardCharsets.UTF_8)));
     }
 
     @Test
@@ -159,7 +160,7 @@ public void shouldCreateHMAC384AlgorithmWithString() throws Exception {
         assertThat(algorithm, is(instanceOf(HMACAlgorithm.class)));
         assertThat(algorithm.getDescription(), is("HmacSHA384"));
         assertThat(algorithm.getName(), is("HS384"));
-        assertThat(((HMACAlgorithm) algorithm).getSecret(), is("secret".getBytes()));
+        assertThat(((HMACAlgorithm) algorithm).getSecret(), is("secret".getBytes(StandardCharsets.UTF_8)));
     }
 
     @Test
@@ -170,7 +171,7 @@ public void shouldCreateHMAC512AlgorithmWithString() throws Exception {
         assertThat(algorithm, is(instanceOf(HMACAlgorithm.class)));
         assertThat(algorithm.getDescription(), is("HmacSHA512"));
         assertThat(algorithm.getName(), is("HS512"));
-        assertThat(((HMACAlgorithm) algorithm).getSecret(), is("secret".getBytes()));
+        assertThat(((HMACAlgorithm) algorithm).getSecret(), is("secret".getBytes(StandardCharsets.UTF_8)));
     }
 
     @Test
diff --git a/lib/src/test/java/com/auth0/jwt/algorithms/AlgorithmUtils.java b/lib/src/test/java/com/auth0/jwt/algorithms/AlgorithmUtils.java
index 10235fee..c8eaccfa 100644
--- a/lib/src/test/java/com/auth0/jwt/algorithms/AlgorithmUtils.java
+++ b/lib/src/test/java/com/auth0/jwt/algorithms/AlgorithmUtils.java
@@ -2,11 +2,13 @@
 
 import org.apache.commons.codec.binary.Base64;
 
+import java.nio.charset.StandardCharsets;
+
 public class AlgorithmUtils {
 
     public static void verify(Algorithm algorithm, String jwt) {
         String[] parts = jwt.split("\\.");
-        byte[] content = String.format("%s.%s", parts[0], parts[1]).getBytes();
+        byte[] content = String.format("%s.%s", parts[0], parts[1]).getBytes(StandardCharsets.UTF_8);
         byte[] signature = new byte[0];
         if (parts.length == 3) {
             signature = Base64.decodeBase64(parts[2]);
diff --git a/lib/src/test/java/com/auth0/jwt/algorithms/ECDSAAlgorithmTest.java b/lib/src/test/java/com/auth0/jwt/algorithms/ECDSAAlgorithmTest.java
index 7dc1108a..c2b8f574 100644
--- a/lib/src/test/java/com/auth0/jwt/algorithms/ECDSAAlgorithmTest.java
+++ b/lib/src/test/java/com/auth0/jwt/algorithms/ECDSAAlgorithmTest.java
@@ -7,6 +7,7 @@
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
 
+import java.nio.charset.StandardCharsets;
 import java.security.*;
 import java.security.interfaces.ECKey;
 import java.security.interfaces.ECPrivateKey;
@@ -352,7 +353,7 @@ public void shouldThrowOnVerifyWhenTheSignatureIsNotPrepared() throws Exception
     public void shouldDoECDSA256Signing() throws Exception {
         Algorithm algorithmSign = Algorithm.ECDSA256((ECKey) readPrivateKeyFromFile(PRIVATE_KEY_FILE_256, "EC"));
         Algorithm algorithmVerify = Algorithm.ECDSA256((ECKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_256, "EC"));
-        byte[] contentBytes = String.format("%s.%s", ES256Header, auth0IssPayload).getBytes();
+        byte[] contentBytes = String.format("%s.%s", ES256Header, auth0IssPayload).getBytes(StandardCharsets.UTF_8);
         byte[] signatureBytes = algorithmSign.sign(contentBytes);
 
         assertThat(signatureBytes, is(notNullValue()));
@@ -374,7 +375,7 @@ public void shouldFailOnECDSA256SigningWhenUsingPublicKey() throws Exception {
     public void shouldDoECDSA384Signing() throws Exception {
         Algorithm algorithmSign = Algorithm.ECDSA384((ECKey) readPrivateKeyFromFile(PRIVATE_KEY_FILE_384, "EC"));
         Algorithm algorithmVerify = Algorithm.ECDSA384((ECKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_384, "EC"));
-        byte[] contentBytes = String.format("%s.%s", ES384Header, auth0IssPayload).getBytes();
+        byte[] contentBytes = String.format("%s.%s", ES384Header, auth0IssPayload).getBytes(StandardCharsets.UTF_8);
         byte[] signatureBytes = algorithmSign.sign(contentBytes);
 
         assertThat(signatureBytes, is(notNullValue()));
@@ -396,7 +397,7 @@ public void shouldFailOnECDSA384SigningWhenUsingPublicKey() throws Exception {
     public void shouldDoECDSA512Signing() throws Exception {
         Algorithm algorithmSign = Algorithm.ECDSA512((ECKey) readPrivateKeyFromFile(PRIVATE_KEY_FILE_512, "EC"));
         Algorithm algorithmVerify = Algorithm.ECDSA512((ECKey) readPublicKeyFromFile(PUBLIC_KEY_FILE_512, "EC"));
-        byte[] contentBytes = String.format("%s.%s", ES512Header, auth0IssPayload).getBytes();
+        byte[] contentBytes = String.format("%s.%s", ES512Header, auth0IssPayload).getBytes(StandardCharsets.UTF_8);
         byte[] signatureBytes = algorithmSign.sign(contentBytes);
 
         assertThat(signatureBytes, is(notNullValue()));
@@ -441,7 +442,7 @@ public void shouldThrowOnSignWhenThePrivateKeyIsInvalid() throws Exception {
 
         ECKey key = mock(ECKey.class, withSettings().extraInterfaces(ECPrivateKey.class));
         Algorithm algorithm = new ECDSAAlgorithm(crypto, "some-alg", "some-algorithm", 32, key);
-        algorithm.sign(ES256Header.getBytes());
+        algorithm.sign(ES256Header.getBytes(StandardCharsets.UTF_8));
     }
 
     @Test
@@ -457,7 +458,7 @@ public void shouldThrowOnSignWhenUsingPublicKey() throws Exception {
 
         ECKey key = mock(ECKey.class, withSettings().extraInterfaces(ECPublicKey.class));
         Algorithm algorithm = new ECDSAAlgorithm(crypto, "some-alg", "some-algorithm", 32, key);
-        algorithm.sign(ES256Header.getBytes());
+        algorithm.sign(ES256Header.getBytes(StandardCharsets.UTF_8));
     }
 
     @Test
@@ -472,6 +473,6 @@ public void shouldThrowOnSignWhenTheSignatureIsNotPrepared() throws Exception {
 
         ECKey key = mock(ECKey.class, withSettings().extraInterfaces(ECPrivateKey.class));
         Algorithm algorithm = new ECDSAAlgorithm(crypto, "some-alg", "some-algorithm", 32, key);
-        algorithm.sign(ES256Header.getBytes());
+        algorithm.sign(ES256Header.getBytes(StandardCharsets.UTF_8));
     }
 }
\ No newline at end of file
diff --git a/lib/src/test/java/com/auth0/jwt/algorithms/HMACAlgorithmTest.java b/lib/src/test/java/com/auth0/jwt/algorithms/HMACAlgorithmTest.java
index 2b063f87..1c8a2012 100644
--- a/lib/src/test/java/com/auth0/jwt/algorithms/HMACAlgorithmTest.java
+++ b/lib/src/test/java/com/auth0/jwt/algorithms/HMACAlgorithmTest.java
@@ -7,6 +7,7 @@
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
 
+import java.nio.charset.StandardCharsets;
 import java.security.InvalidKeyException;
 import java.security.NoSuchAlgorithmException;
 import java.util.Arrays;
@@ -153,8 +154,8 @@ public void shouldThrowOnVerifyWhenTheSecretIsInvalid() throws Exception {
 
     @Test
     public void shouldDoHMAC256SigningWithBytes() throws Exception {
-        Algorithm algorithm = Algorithm.HMAC256("secret".getBytes());
-        byte[] contentBytes = String.format("%s.%s", HS256Header, auth0IssPayload).getBytes();
+        Algorithm algorithm = Algorithm.HMAC256("secret".getBytes(StandardCharsets.UTF_8));
+        byte[] contentBytes = String.format("%s.%s", HS256Header, auth0IssPayload).getBytes(StandardCharsets.UTF_8);
         byte[] signatureBytes = algorithm.sign(contentBytes);
         String signature = Base64.encodeBase64URLSafeString(signatureBytes);
         String expectedSignature = "s69x7Mmu4JqwmdxiK6sesALO7tcedbFsKEEITUxw9ho";
@@ -166,8 +167,8 @@ public void shouldDoHMAC256SigningWithBytes() throws Exception {
 
     @Test
     public void shouldDoHMAC384SigningWithBytes() throws Exception {
-        Algorithm algorithm = Algorithm.HMAC384("secret".getBytes());
-        byte[] contentBytes = String.format("%s.%s", HS384Header, auth0IssPayload).getBytes();
+        Algorithm algorithm = Algorithm.HMAC384("secret".getBytes(StandardCharsets.UTF_8));
+        byte[] contentBytes = String.format("%s.%s", HS384Header, auth0IssPayload).getBytes(StandardCharsets.UTF_8);
         byte[] signatureBytes = algorithm.sign(contentBytes);
         String signature = Base64.encodeBase64URLSafeString(signatureBytes);
         String expectedSignature = "4-y2Gxz_foN0jAOFimmBPF7DWxf4AsjM20zxNkHg8Zah5Q64G42P9GfjmUp4Hldt";
@@ -179,8 +180,8 @@ public void shouldDoHMAC384SigningWithBytes() throws Exception {
 
     @Test
     public void shouldDoHMAC512SigningWithBytes() throws Exception {
-        Algorithm algorithm = Algorithm.HMAC512("secret".getBytes());
-        byte[] contentBytes = String.format("%s.%s", HS512Header, auth0IssPayload).getBytes();
+        Algorithm algorithm = Algorithm.HMAC512("secret".getBytes(StandardCharsets.UTF_8));
+        byte[] contentBytes = String.format("%s.%s", HS512Header, auth0IssPayload).getBytes(StandardCharsets.UTF_8);
         byte[] signatureBytes = algorithm.sign(contentBytes);
         String signature = Base64.encodeBase64URLSafeString(signatureBytes);
         String expectedSignature = "OXWyxmf-VcVo8viOiTFfLaEy6mrQqLEos5R82Xsx8mtFxQadJAQ1aVniIWN8qT2GNE_pMQPcdzk4x7Cqxsp1dw";
@@ -193,7 +194,7 @@ public void shouldDoHMAC512SigningWithBytes() throws Exception {
     @Test
     public void shouldDoHMAC256SigningWithString() throws Exception {
         Algorithm algorithm = Algorithm.HMAC256("secret");
-        byte[] contentBytes = String.format("%s.%s", HS256Header, auth0IssPayload).getBytes();
+        byte[] contentBytes = String.format("%s.%s", HS256Header, auth0IssPayload).getBytes(StandardCharsets.UTF_8);
         byte[] signatureBytes = algorithm.sign(contentBytes);
         String signature = Base64.encodeBase64URLSafeString(signatureBytes);
         String expectedSignature = "s69x7Mmu4JqwmdxiK6sesALO7tcedbFsKEEITUxw9ho";
@@ -206,7 +207,7 @@ public void shouldDoHMAC256SigningWithString() throws Exception {
     @Test
     public void shouldDoHMAC384SigningWithString() throws Exception {
         Algorithm algorithm = Algorithm.HMAC384("secret");
-        byte[] contentBytes = String.format("%s.%s", HS384Header, auth0IssPayload).getBytes();
+        byte[] contentBytes = String.format("%s.%s", HS384Header, auth0IssPayload).getBytes(StandardCharsets.UTF_8);
         byte[] signatureBytes = algorithm.sign(contentBytes);
         String signature = Base64.encodeBase64URLSafeString(signatureBytes);
         String expectedSignature = "4-y2Gxz_foN0jAOFimmBPF7DWxf4AsjM20zxNkHg8Zah5Q64G42P9GfjmUp4Hldt";
@@ -219,7 +220,7 @@ public void shouldDoHMAC384SigningWithString() throws Exception {
     @Test
     public void shouldDoHMAC512SigningWithString() throws Exception {
         Algorithm algorithm = Algorithm.HMAC512("secret");
-        byte[] contentBytes = String.format("%s.%s", HS512Header, auth0IssPayload).getBytes();
+        byte[] contentBytes = String.format("%s.%s", HS512Header, auth0IssPayload).getBytes(StandardCharsets.UTF_8);
         byte[] signatureBytes = algorithm.sign(contentBytes);
         String signature = Base64.encodeBase64URLSafeString(signatureBytes);
         String expectedSignature = "OXWyxmf-VcVo8viOiTFfLaEy6mrQqLEos5R82Xsx8mtFxQadJAQ1aVniIWN8qT2GNE_pMQPcdzk4x7Cqxsp1dw";
@@ -239,7 +240,7 @@ public void shouldThrowOnSignWhenSignatureAlgorithmDoesNotExists() throws Except
         when(crypto.createSignatureFor(anyString(), any(byte[].class), any(byte[].class)))
                 .thenThrow(NoSuchAlgorithmException.class);
 
-        Algorithm algorithm = new HMACAlgorithm(crypto, "some-alg", "some-algorithm", "secret".getBytes());
+        Algorithm algorithm = new HMACAlgorithm(crypto, "some-alg", "some-algorithm", "secret".getBytes(StandardCharsets.UTF_8));
         algorithm.sign(new byte[0]);
     }
 
@@ -253,7 +254,7 @@ public void shouldThrowOnSignWhenTheSecretIsInvalid() throws Exception {
         when(crypto.createSignatureFor(anyString(), any(byte[].class), any(byte[].class)))
                 .thenThrow(InvalidKeyException.class);
 
-        Algorithm algorithm = new HMACAlgorithm(crypto, "some-alg", "some-algorithm", "secret".getBytes());
+        Algorithm algorithm = new HMACAlgorithm(crypto, "some-alg", "some-algorithm", "secret".getBytes(StandardCharsets.UTF_8));
         algorithm.sign(new byte[0]);
     }
 
diff --git a/lib/src/test/java/com/auth0/jwt/algorithms/RSAAlgorithmTest.java b/lib/src/test/java/com/auth0/jwt/algorithms/RSAAlgorithmTest.java
index 203f3ce2..ea6961fc 100644
--- a/lib/src/test/java/com/auth0/jwt/algorithms/RSAAlgorithmTest.java
+++ b/lib/src/test/java/com/auth0/jwt/algorithms/RSAAlgorithmTest.java
@@ -7,6 +7,7 @@
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
 
+import java.nio.charset.StandardCharsets;
 import java.security.*;
 import java.security.interfaces.RSAKey;
 import java.security.interfaces.RSAPrivateKey;
@@ -174,7 +175,7 @@ public void shouldDoRSA256Signing() throws Exception {
         Algorithm algorithmSign = Algorithm.RSA256((RSAKey) readPrivateKeyFromFile(PRIVATE_KEY_FILE, "RSA"));
         Algorithm algorithmVerify = Algorithm.RSA256((RSAKey) readPublicKeyFromFile(PUBLIC_KEY_FILE, "RSA"));
 
-        byte[] contentBytes = String.format("%s.%s", RS256Header, auth0IssPayload).getBytes();
+        byte[] contentBytes = String.format("%s.%s", RS256Header, auth0IssPayload).getBytes(StandardCharsets.UTF_8);
         byte[] signatureBytes = algorithmSign.sign(contentBytes);
         String signature = Base64.encodeBase64URLSafeString(signatureBytes);
         String expectedSignature = "ZB-Tr0vLtnf8I9fhSdSjU6HZei5xLYZQ6nZqM5O6Va0W9PgAqgRT7ShI9CjeYulRXPHvVmSl5EQuYuXdBzM0-H_3p_Nsl6tSMy4EyX2kkhEm6T0HhvarTh8CG0PCjn5p6FP5ZxWwhLcmRN70ItP6Z5MMO4CcJh1JrNxR4Fi4xQgt-CK2aVDMFXd-Br5yQiLVx1CX83w28OD9wssW3Rdltl5e66vCef0Ql6Q5I5e5F0nqGYT989a9fkNgLIx2F8k_az5x07BY59FV2SZg59nSiY7TZNjP8ot11Ew7HKRfPXOdh9eKRUVdhcxzqDePhyzKabU8TG5FP0SiWH5qVPfAgw";
@@ -200,7 +201,7 @@ public void shouldDoRSA384Signing() throws Exception {
         Algorithm algorithmSign = Algorithm.RSA384((RSAKey) readPrivateKeyFromFile(PRIVATE_KEY_FILE, "RSA"));
         Algorithm algorithmVerify = Algorithm.RSA384((RSAKey) readPublicKeyFromFile(PUBLIC_KEY_FILE, "RSA"));
 
-        byte[] contentBytes = String.format("%s.%s", RS384Header, auth0IssPayload).getBytes();
+        byte[] contentBytes = String.format("%s.%s", RS384Header, auth0IssPayload).getBytes(StandardCharsets.UTF_8);
         byte[] signatureBytes = algorithmSign.sign(contentBytes);
         String signature = Base64.encodeBase64URLSafeString(signatureBytes);
         String expectedSignature = "Jx1PaTBnjd_U56MNjifFcY7w9ImDbseg0y8Ijr2pSiA1_wzQb_wy9undaWfzR5YqdIAXvjS8AGuZUAzIoTG4KMgOgdVyYDz3l2jzj6wI-lgqfR5hTy1w1ruMUQ4_wobpdxAiJ4fEbg8Mi_GljOiCO-P1HilxKnpiOJZidR8MQGwTInsf71tOUkK4x5UsdmUueuZbaU-CL5kPnRfXmJj9CcdxZbD9oMlbo23dwkP5BNMrS2LwGGzc9C_-ypxrBIOVilG3WZxcSmuG86LjcZbnL6LBEfph5NmKBgQav147uipb_7umBEr1m2dYiB_9u606n3bcoo3rnsYYK_Xfi1GAEQ";
@@ -226,7 +227,7 @@ public void shouldDoRSA512Signing() throws Exception {
         Algorithm algorithmSign = Algorithm.RSA512((RSAKey) readPrivateKeyFromFile(PRIVATE_KEY_FILE, "RSA"));
         Algorithm algorithmVerify = Algorithm.RSA512((RSAKey) readPublicKeyFromFile(PUBLIC_KEY_FILE, "RSA"));
 
-        byte[] contentBytes = String.format("%s.%s", RS512Header, auth0IssPayload).getBytes();
+        byte[] contentBytes = String.format("%s.%s", RS512Header, auth0IssPayload).getBytes(StandardCharsets.UTF_8);
         byte[] signatureBytes = algorithmSign.sign(contentBytes);
         String signature = Base64.encodeBase64URLSafeString(signatureBytes);
         String expectedSignature = "THIPVYzNZ1Yo_dm0k1UELqV0txs3SzyMopCyHcLXOOdgYXF4MlGvBqu0CFvgSga72Sp5LpuC1Oesj40v_QDsp2GTGDeWnvvcv_eo-b0LPSpmT2h1Ibrmu-z70u2rKf28pkN-AJiMFqi8sit2kMIp1bwIVOovPvMTQKGFmova4Xwb3G526y_PeLlflW1h69hQTIVcI67ACEkAC-byjDnnYIklA-B4GWcggEoFwQRTdRjAUpifA6HOlvnBbZZlUd6KXwEydxVS-eh1odwPjB2_sfbyy5HnLsvNdaniiZQwX7QbwLNT4F72LctYdHHM1QCrID6bgfgYp9Ij9CRX__XDEA";
@@ -259,7 +260,7 @@ public void shouldThrowOnSignWhenSignatureAlgorithmDoesNotExists() throws Except
 
         RSAKey key = mock(RSAKey.class, withSettings().extraInterfaces(RSAPrivateKey.class));
         Algorithm algorithm = new RSAAlgorithm(crypto, "some-alg", "some-algorithm", key);
-        algorithm.sign(RS256Header.getBytes());
+        algorithm.sign(RS256Header.getBytes(StandardCharsets.UTF_8));
     }
 
     @Test
@@ -274,7 +275,7 @@ public void shouldThrowOnSignWhenThePrivateKeyIsInvalid() throws Exception {
 
         RSAKey key = mock(RSAKey.class, withSettings().extraInterfaces(RSAPrivateKey.class));
         Algorithm algorithm = new RSAAlgorithm(crypto, "some-alg", "some-algorithm", key);
-        algorithm.sign(RS256Header.getBytes());
+        algorithm.sign(RS256Header.getBytes(StandardCharsets.UTF_8));
     }
 
     @Test
@@ -290,7 +291,7 @@ public void shouldThrowOnSignWhenUsingPublicKey() throws Exception {
 
         RSAKey key = mock(RSAKey.class, withSettings().extraInterfaces(RSAPublicKey.class));
         Algorithm algorithm = new RSAAlgorithm(crypto, "some-alg", "some-algorithm", key);
-        algorithm.sign(RS256Header.getBytes());
+        algorithm.sign(RS256Header.getBytes(StandardCharsets.UTF_8));
     }
 
     @Test
@@ -305,6 +306,6 @@ public void shouldThrowOnSignWhenTheSignatureIsNotPrepared() throws Exception {
 
         RSAKey key = mock(RSAKey.class, withSettings().extraInterfaces(RSAPrivateKey.class));
         Algorithm algorithm = new RSAAlgorithm(crypto, "some-alg", "some-algorithm", key);
-        algorithm.sign(RS256Header.getBytes());
+        algorithm.sign(RS256Header.getBytes(StandardCharsets.UTF_8));
     }
 }
\ No newline at end of file