diff --git a/classpath/java/lang/Boolean.java b/classpath/java/lang/Boolean.java
index be44e955d5..e2b6a10fbf 100644
--- a/classpath/java/lang/Boolean.java
+++ b/classpath/java/lang/Boolean.java
@@ -1,6 +1,6 @@
 package java.lang;
 
-public final class Boolean {
+public final class Boolean implements Comparable<Boolean> {
   public static final Class TYPE = Class.forCanonicalName("Z");
 
   public static final Boolean FALSE = new Boolean(false);
@@ -24,6 +24,10 @@ public final class Boolean {
     return ("true".equals(s) ? Boolean.TRUE : Boolean.FALSE);
   }
 
+  public int compareTo(Boolean o) {
+    return (value ? (o.value ? 0 : 1) : (o.value ? -1 : 0));
+  }
+
   public boolean equals(Object o) {
     return o instanceof Boolean && ((Boolean) o).value == value;
   }
diff --git a/classpath/java/lang/Byte.java b/classpath/java/lang/Byte.java
index 3007906695..1d1f4caac2 100644
--- a/classpath/java/lang/Byte.java
+++ b/classpath/java/lang/Byte.java
@@ -1,6 +1,6 @@
 package java.lang;
 
-public final class Byte extends Number {
+public final class Byte extends Number implements Comparable<Byte> {
   public static final Class TYPE = Class.forCanonicalName("B");
 
   private final byte value;
@@ -25,6 +25,10 @@ public final class Byte extends Number {
     return toString(value);
   }
 
+  public int compareTo(Byte o) {
+    return value - o.value;
+  }
+
   public static String toString(byte v, int radix) {
     return Long.toString(v, radix);
   }
diff --git a/classpath/java/lang/Character.java b/classpath/java/lang/Character.java
index dd7658d52b..b5543e9e5c 100644
--- a/classpath/java/lang/Character.java
+++ b/classpath/java/lang/Character.java
@@ -1,6 +1,6 @@
 package java.lang;
 
-public final class Character {
+public final class Character implements Comparable<Character> {
   public static final Class TYPE = Class.forCanonicalName("C");
 
   private final char value;
@@ -13,6 +13,10 @@ public final class Character {
     return new Character(value);
   }
 
+  public int compareTo(Character o) {
+    return value - o.value;
+  }
+
   public boolean equals(Object o) {
     return o instanceof Character && ((Character) o).value == value;
   }
diff --git a/classpath/java/lang/Long.java b/classpath/java/lang/Long.java
index 401d31492f..013ac883bb 100644
--- a/classpath/java/lang/Long.java
+++ b/classpath/java/lang/Long.java
@@ -1,6 +1,6 @@
 package java.lang;
 
-public final class Long extends Number {
+public final class Long extends Number implements Comparable<Long> {
   public static final Class TYPE = Class.forCanonicalName("J");
   public static final Long MAX_VALUE = 9223372036854775807l;
 
@@ -22,6 +22,10 @@ public final class Long extends Number {
     return new Long(value);
   }
 
+  public int compareTo(Long o) {
+    return value > o.value ? 1 : (value < o.value ? -1 : 0);
+  }
+
   public boolean equals(Object o) {
     return o instanceof Long && ((Long) o).value == value;
   }
diff --git a/classpath/java/lang/Short.java b/classpath/java/lang/Short.java
index 8c3834eff6..bfca752af5 100644
--- a/classpath/java/lang/Short.java
+++ b/classpath/java/lang/Short.java
@@ -1,6 +1,6 @@
 package java.lang;
 
-public final class Short extends Number {
+public final class Short extends Number implements Comparable<Short> {
   public static final Class TYPE = Class.forCanonicalName("S");
   public static final short MAX_VALUE = 32767;
 
@@ -14,6 +14,10 @@ public final class Short extends Number {
     return new Short(value);
   }
 
+  public int compareTo(Short o) {
+    return value - o.value;
+  }
+
   public boolean equals(Object o) {
     return o instanceof Short && ((Short) o).value == value;
   }