diff --git a/contrib/benchmark/src/java/org/apache/lucene/benchmark/quality/QualityQuery.java b/contrib/benchmark/src/java/org/apache/lucene/benchmark/quality/QualityQuery.java
index ca5ec0512b7..809dc209f95 100755
--- a/contrib/benchmark/src/java/org/apache/lucene/benchmark/quality/QualityQuery.java
+++ b/contrib/benchmark/src/java/org/apache/lucene/benchmark/quality/QualityQuery.java
@@ -32,7 +32,7 @@ import java.util.Map;
  * or each pair as its own field, etc., - and this of course must match the way the 
  * searched index was constructed.
  */
-public class QualityQuery implements Comparable {
+public class QualityQuery implements Comparable<QualityQuery> {
   private String queryID;
   private Map nameValPairs;
 
@@ -71,8 +71,7 @@ public class QualityQuery implements Comparable {
 
   /* for a nicer sort of input queries before running them.
    * Try first as ints, fall back to string if not int. */ 
-  public int compareTo(Object o) {
-    QualityQuery other = (QualityQuery) o;
+  public int compareTo(QualityQuery other) {
     try {
       // compare as ints when ids ints
       int n = Integer.parseInt(queryID);
diff --git a/contrib/surround/src/java/org/apache/lucene/queryParser/surround/query/SimpleTerm.java b/contrib/surround/src/java/org/apache/lucene/queryParser/surround/query/SimpleTerm.java
index 9f55e477906..be7edc68c36 100644
--- a/contrib/surround/src/java/org/apache/lucene/queryParser/surround/query/SimpleTerm.java
+++ b/contrib/surround/src/java/org/apache/lucene/queryParser/surround/query/SimpleTerm.java
@@ -27,7 +27,7 @@ import org.apache.lucene.search.Query;
 
 public abstract class SimpleTerm
   extends SrndQuery
-  implements DistanceSubQuery, Comparable
+  implements DistanceSubQuery, Comparable<SimpleTerm>
 {
   public SimpleTerm(boolean q) {quoted = q;}
   
@@ -39,9 +39,8 @@ public abstract class SimpleTerm
   
   public abstract String toStringUnquoted();
   
-  public int compareTo(Object o) {
+  public int compareTo(SimpleTerm ost) {
     /* for ordering terms and prefixes before using an index, not used */
-    SimpleTerm ost = (SimpleTerm) o;
     return this.toStringUnquoted().compareTo( ost.toStringUnquoted());
   }
   
diff --git a/src/java/org/apache/lucene/index/FreqProxTermsWriterPerField.java b/src/java/org/apache/lucene/index/FreqProxTermsWriterPerField.java
index 3863fdc7b05..5e4038bc8ee 100644
--- a/src/java/org/apache/lucene/index/FreqProxTermsWriterPerField.java
+++ b/src/java/org/apache/lucene/index/FreqProxTermsWriterPerField.java
@@ -24,7 +24,7 @@ import org.apache.lucene.analysis.tokenattributes.PayloadAttribute;
 // TODO: break into separate freq and prox writers as
 // codecs; make separate container (tii/tis/skip/*) that can
 // be configured as any number of files 1..N
-final class FreqProxTermsWriterPerField extends TermsHashConsumerPerField implements Comparable {
+final class FreqProxTermsWriterPerField extends TermsHashConsumerPerField implements Comparable<FreqProxTermsWriterPerField> {
 
   final FreqProxTermsWriterPerThread perThread;
   final TermsHashPerField termsHashPerField;
@@ -56,8 +56,7 @@ final class FreqProxTermsWriterPerField extends TermsHashConsumerPerField implem
 
   void skippingLongTerm() throws IOException {}
 
-  public int compareTo(Object other0) {
-    FreqProxTermsWriterPerField other = (FreqProxTermsWriterPerField) other0;
+  public int compareTo(FreqProxTermsWriterPerField other) {
     return fieldInfo.name.compareTo(other.fieldInfo.name);
   }
 
diff --git a/src/java/org/apache/lucene/index/IndexFileDeleter.java b/src/java/org/apache/lucene/index/IndexFileDeleter.java
index d974372925d..6313586b6c4 100644
--- a/src/java/org/apache/lucene/index/IndexFileDeleter.java
+++ b/src/java/org/apache/lucene/index/IndexFileDeleter.java
@@ -567,7 +567,7 @@ final class IndexFileDeleter {
    * equals.
    */
 
-  final private static class CommitPoint extends IndexCommit implements Comparable {
+  final private static class CommitPoint extends IndexCommit implements Comparable<CommitPoint> {
 
     long gen;
     Collection files;
@@ -637,8 +637,7 @@ final class IndexFileDeleter {
       return deleted;
     }
 
-    public int compareTo(Object obj) {
-      CommitPoint commit = (CommitPoint) obj;
+    public int compareTo(CommitPoint commit) {
       if (gen < commit.gen) {
         return -1;
       } else if (gen > commit.gen) {
diff --git a/src/java/org/apache/lucene/index/NormsWriterPerField.java b/src/java/org/apache/lucene/index/NormsWriterPerField.java
index 34364de5af7..52c08f03b6e 100644
--- a/src/java/org/apache/lucene/index/NormsWriterPerField.java
+++ b/src/java/org/apache/lucene/index/NormsWriterPerField.java
@@ -25,7 +25,7 @@ import org.apache.lucene.search.Similarity;
  *  just look at the length for the field (docState.length)
  *  and record the norm. */
 
-final class NormsWriterPerField extends InvertedDocEndConsumerPerField implements Comparable {
+final class NormsWriterPerField extends InvertedDocEndConsumerPerField implements Comparable<NormsWriterPerField> {
 
   final NormsWriterPerThread perThread;
   final FieldInfo fieldInfo;
@@ -56,8 +56,8 @@ final class NormsWriterPerField extends InvertedDocEndConsumerPerField implement
     upto = 0;
   }
 
-  public int compareTo(Object other) {
-    return fieldInfo.name.compareTo(((NormsWriterPerField) other).fieldInfo.name);
+  public int compareTo(NormsWriterPerField other) {
+    return fieldInfo.name.compareTo(other.fieldInfo.name);
   }
   
   void finish() {
diff --git a/src/test/org/apache/lucene/index/TestTermVectorsReader.java b/src/test/org/apache/lucene/index/TestTermVectorsReader.java
index f7e55ac1f58..2c9dd3f3da2 100644
--- a/src/test/org/apache/lucene/index/TestTermVectorsReader.java
+++ b/src/test/org/apache/lucene/index/TestTermVectorsReader.java
@@ -25,6 +25,7 @@ import java.util.Map;
 import java.util.SortedSet;
 
 import org.apache.lucene.analysis.Analyzer;
+import org.apache.lucene.analysis.Token;
 import org.apache.lucene.analysis.TokenStream;
 import org.apache.lucene.analysis.tokenattributes.OffsetAttribute;
 import org.apache.lucene.analysis.tokenattributes.PositionIncrementAttribute;
@@ -51,13 +52,13 @@ public class TestTermVectorsReader extends LuceneTestCase {
     super(s);
   }
   
-  private class TestToken implements Comparable {
+  private class TestToken implements Comparable<TestToken> {
     String text;
     int pos;
     int startOffset;
     int endOffset;
-    public int compareTo(Object other) {
-      return pos - ((TestToken) other).pos;
+    public int compareTo(TestToken other) {
+      return pos - other.pos;
     }
   }