diff --git a/.gitignore b/.gitignore
index 5ab9b34a..b5766efd 100644
--- a/.gitignore
+++ b/.gitignore
@@ -57,6 +57,11 @@ crashlytics.properties
 crashlytics-build.properties
 fabric.properties
 
+# Eclipse IDE
+.classpath
+.project
+.settings/
+
 ### Java template
 *.class
 
diff --git a/lib/src/main/java/com/auth0/jwt/impl/NullClaim.java b/lib/src/main/java/com/auth0/jwt/impl/NullClaim.java
index 8d10ca10..2e9a38c2 100644
--- a/lib/src/main/java/com/auth0/jwt/impl/NullClaim.java
+++ b/lib/src/main/java/com/auth0/jwt/impl/NullClaim.java
@@ -8,7 +8,7 @@
 import java.util.Map;
 
 /**
- * The {@link NullClaim} class is a Claim implementation that returns null when any of it's methods it's called.
+ * The {@code NullClaim} class is a Claim implementation that returns null when any of it's methods is called.
  */
 public class NullClaim implements Claim {
     @Override
diff --git a/lib/src/main/java/com/auth0/jwt/impl/package-info.java b/lib/src/main/java/com/auth0/jwt/impl/package-info.java
new file mode 100644
index 00000000..334ccb8a
--- /dev/null
+++ b/lib/src/main/java/com/auth0/jwt/impl/package-info.java
@@ -0,0 +1,7 @@
+/**
+ * Contains parts of the <b>internal</b> implementation of this library.
+ *
+ * <p><b>Do not use any of the classes in this package.</b> They might be removed
+ * or changed at any point without prior warning.
+ */
+package com.auth0.jwt.impl;
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 0a83d1ce..030643d0 100644
--- a/lib/src/main/java/com/auth0/jwt/interfaces/Header.java
+++ b/lib/src/main/java/com/auth0/jwt/interfaces/Header.java
@@ -34,7 +34,8 @@ public interface Header {
     String getKeyId();
 
     /**
-     * Get a Private Claim given it's name. If the Claim wasn't specified in the Header, a NullClaim will be returned.
+     * Get a Private Claim given it's name. If the Claim wasn't specified in the Header, a 'null claim' will be
+     * returned. All of the methods of that claim will return {@code null}.
      *
      * @param name the name of the Claim to retrieve.
      * @return a non-null Claim.
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 0f639ab9..b999ad43 100644
--- a/lib/src/main/java/com/auth0/jwt/interfaces/Payload.java
+++ b/lib/src/main/java/com/auth0/jwt/interfaces/Payload.java
@@ -59,7 +59,8 @@ public interface Payload {
     String getId();
 
     /**
-     * Get a Claim given it's name. If the Claim wasn't specified in the Payload, a NullClaim will be returned.
+     * Get a Claim given it's name. If the Claim wasn't specified in the Payload, a 'null claim'
+     * will be returned. All of the methods of that claim will return {@code null}.
      *
      * @param name the name of the Claim to retrieve.
      * @return a non-null Claim.