diff --git a/build.xml b/build.xml
index 688a08068..01f9fd587 100644
--- a/build.xml
+++ b/build.xml
@@ -182,7 +182,7 @@
     <!-- start of a change to turn on compilation of all input files -->
     <!-- under JDK1.5. -->
     <property name="testExcludes"
-              value="**/grammars/*,**/j2ee/*,**/InputAssertIdentifier.java,**/InputSimple.java,**/InputTags.java,**/InputJUnitTest.java,**/InputValidMethodIndent.java,**/InputSetterGetter.java,**/InputImport.java,**/InputUnusedMethod.java"/>
+              value="**/grammars/*,**/j2ee/*,**/InputAssertIdentifier.java,**/InputJUnitTest.java,**/InputValidMethodIndent.java,**/InputSetterGetter.java,**/InputImport.java,**/InputCovariant.java,**/InputClone.java,**/InputSimple.java"/>
     <javac srcdir="src/testinputs"
            destdir="target/testinputs"
            deprecation="on" debug="on"
diff --git a/src/checkstyle/com/puppycrawl/tools/checkstyle/checks/usage/AbstractUsageCheck.java b/src/checkstyle/com/puppycrawl/tools/checkstyle/checks/usage/AbstractUsageCheck.java
index 5d4962c3f..52a815309 100644
--- a/src/checkstyle/com/puppycrawl/tools/checkstyle/checks/usage/AbstractUsageCheck.java
+++ b/src/checkstyle/com/puppycrawl/tools/checkstyle/checks/usage/AbstractUsageCheck.java
@@ -108,6 +108,10 @@ public abstract class AbstractUsageCheck
     /** @see com.puppycrawl.tools.checkstyle.api.Check */
     public void finishTree(DetailAST aAST)
     {
+        if (aAST == null) {
+            // we have nothing to check
+            return;
+        }
         try {
             final Set nodes = getASTManager().getCheckNodes(this);
             if (nodes != null) {
diff --git a/src/testinputs/com/puppycrawl/tools/checkstyle/InputTags.java b/src/testinputs/com/puppycrawl/tools/checkstyle/InputTags.java
index 1daa14daf..a6b1a7e9f 100644
--- a/src/testinputs/com/puppycrawl/tools/checkstyle/InputTags.java
+++ b/src/testinputs/com/puppycrawl/tools/checkstyle/InputTags.java
@@ -269,7 +269,7 @@ class InputTags1
 
     /** {@inheritDoc} */
     int method26()
-    {
+    { return 0;
     }
 
     /** 
@@ -277,7 +277,7 @@ class InputTags1
      * @return something very important.
      */
     int method27(int aParam)
-    {
+    { return 0;
     }
 
     /** 
@@ -285,7 +285,7 @@ class InputTags1
      * {@inheritDoc}
      */
     int method28(int aParam)
-    {
+    { return 0;
     }
 
     /**
@@ -359,3 +359,10 @@ public class InputTags {
         return null;
     }
 }
+
+/**
+ *  Added to make this file compilable.
+ */
+class WrongException extends RuntimeException
+{
+}
diff --git a/src/testinputs/com/puppycrawl/tools/checkstyle/coding/InputClone.java b/src/testinputs/com/puppycrawl/tools/checkstyle/coding/InputClone.java
index 45cdd9c8c..8401308f4 100644
--- a/src/testinputs/com/puppycrawl/tools/checkstyle/coding/InputClone.java
+++ b/src/testinputs/com/puppycrawl/tools/checkstyle/coding/InputClone.java
@@ -51,7 +51,7 @@ class CloneWithTypeArguments
 {
     public <T> Object clone()
     {
-        super.<T>clone();
+        return super.<T>clone();
     }
 }
 
@@ -70,4 +70,4 @@ class MyClassWithGenericSuperMethod
     {
 
     }
-}
\ No newline at end of file
+}
diff --git a/src/testinputs/com/puppycrawl/tools/checkstyle/coding/InputExplicitInit.java b/src/testinputs/com/puppycrawl/tools/checkstyle/coding/InputExplicitInit.java
index 573773537..ef243bf94 100644
--- a/src/testinputs/com/puppycrawl/tools/checkstyle/coding/InputExplicitInit.java
+++ b/src/testinputs/com/puppycrawl/tools/checkstyle/coding/InputExplicitInit.java
@@ -60,11 +60,14 @@ enum InputExplicitInit3 {
 }
 
 class ForEach {
-    public ForEach(Collection<String> strings)
+    public ForEach(java.util.Collection<String> strings)
     {
         for(String s : strings) //this should not even be checked
         {
 
         }
     }
-}
\ No newline at end of file
+}
+
+class Bar<T> {
+}
diff --git a/src/testinputs/com/puppycrawl/tools/checkstyle/coding/InputFinalize.java b/src/testinputs/com/puppycrawl/tools/checkstyle/coding/InputFinalize.java
index 72c1ea7d8..535208e9f 100644
--- a/src/testinputs/com/puppycrawl/tools/checkstyle/coding/InputFinalize.java
+++ b/src/testinputs/com/puppycrawl/tools/checkstyle/coding/InputFinalize.java
@@ -44,10 +44,10 @@ class InnerFinalize
 }
 
 //Check that super keword isn't snagged here
-class MyClassWithGenericSuperMethod
+class MyClassWithGenericSuperMethod1
 {
     void someMethod(java.util.List<? super java.util.Map> l)
     {
 
     }
-}
\ No newline at end of file
+}
diff --git a/src/testinputs/com/puppycrawl/tools/checkstyle/usage/InputEmptyFile.java b/src/testinputs/com/puppycrawl/tools/checkstyle/usage/InputEmptyFile.java
new file mode 100644
index 000000000..bb7db0ea4
--- /dev/null
+++ b/src/testinputs/com/puppycrawl/tools/checkstyle/usage/InputEmptyFile.java
@@ -0,0 +1,2 @@
+// this is an empty file
+// it's a test for 1165855
diff --git a/src/testinputs/com/puppycrawl/tools/checkstyle/usage/InputUnusedMethod.java b/src/testinputs/com/puppycrawl/tools/checkstyle/usage/InputUnusedMethod.java
index 78037508c..6aa8b6b2e 100644
--- a/src/testinputs/com/puppycrawl/tools/checkstyle/usage/InputUnusedMethod.java
+++ b/src/testinputs/com/puppycrawl/tools/checkstyle/usage/InputUnusedMethod.java
@@ -86,7 +86,7 @@ class SerializableTest implements java.io.Serializable
     }
 }
 
-class BadSerializableTest implements java.io.Serializable
+class BadSerializableTest1 implements java.io.Serializable
 {
     private void writeObject(Object out) throws java.io.IOException
     {
@@ -100,36 +100,19 @@ class BadSerializableTest implements java.io.Serializable
     {
     }
 
-    private int writeObject(java.io.ObjectOutputStream out) throws java.io.IOException
-    {
-    }
-
     private void readObject(java.io.ObjectInputStream in) throws java.io.IOException
     {
     }
 
-    private void readObject(java.io.ObjectInputStream in) throws ClassNotFoundException
-    {
-    }
-
     private void readObject(Object in) throws java.io.IOException, ClassNotFoundException
     {
     }
 
-    private int readObject(java.io.ObjectInputStream in) throws java.io.IOException, ClassNotFoundException
-    {
-    }
-
     private int writeReplace() throws java.io.ObjectStreamException
     {
         return 1;
     }
 
-    private java.lang.Object writeReplace()
-    {
-        return new SerializableTest();
-    }
-
     private Object writeReplace(int i) throws java.io.ObjectStreamException
     {
         return new SerializableTest();
@@ -140,13 +123,33 @@ class BadSerializableTest implements java.io.Serializable
         return 1;
     }
 
-    private Object readResolve()
-    {
-        return new SerializableTest();
-    }
-
     private Object readResolve(int i) throws java.io.ObjectStreamException
     {
         return new SerializableTest();
     }
 }
+
+class BadSerializableTest2 implements java.io.Serializable
+{
+    private int writeObject(java.io.ObjectOutputStream out) throws java.io.IOException
+    {
+        return 1;
+    }
+
+    private void readObject(java.io.ObjectInputStream in) throws ClassNotFoundException
+    {
+    }
+
+    private Object readResolve()
+    {
+        return new SerializableTest();
+    }
+}
+
+class BadSerializableTest3 implements java.io.Serializable
+{
+    private int readObject(java.io.ObjectInputStream in) throws java.io.IOException, ClassNotFoundException
+    {
+        return 1;
+    }
+}
diff --git a/src/tests/com/puppycrawl/tools/checkstyle/checks/usage/UnusedPrivateMethodCheckTest.java b/src/tests/com/puppycrawl/tools/checkstyle/checks/usage/UnusedPrivateMethodCheckTest.java
index b2e5cd32c..d37077b4f 100644
--- a/src/tests/com/puppycrawl/tools/checkstyle/checks/usage/UnusedPrivateMethodCheckTest.java
+++ b/src/tests/com/puppycrawl/tools/checkstyle/checks/usage/UnusedPrivateMethodCheckTest.java
@@ -19,17 +19,16 @@ public class UnusedPrivateMethodCheckTest
             "91:18: Unused private method 'writeObject'.",
             "95:18: Unused private method 'writeObject'.",
             "99:18: Unused private method 'writeObject'.",
-            "103:17: Unused private method 'writeObject'.",
+            "103:18: Unused private method 'readObject'.",
             "107:18: Unused private method 'readObject'.",
-            "111:18: Unused private method 'readObject'.",
-            "115:18: Unused private method 'readObject'.",
-            "119:17: Unused private method 'readObject'.",
-            "123:17: Unused private method 'writeReplace'.",
-            "128:30: Unused private method 'writeReplace'.",
-            "133:20: Unused private method 'writeReplace'.",
-            "138:17: Unused private method 'readResolve'.",
+            "111:17: Unused private method 'writeReplace'.",
+            "116:20: Unused private method 'writeReplace'.",
+            "121:17: Unused private method 'readResolve'.",
+            "126:20: Unused private method 'readResolve'.",
+            "134:17: Unused private method 'writeObject'.",
+            "139:18: Unused private method 'readObject'.",
             "143:20: Unused private method 'readResolve'.",
-            "148:20: Unused private method 'readResolve'.",
+            "151:17: Unused private method 'readObject'.",
         };
         verify(checkConfig, getPath("usage/InputUnusedMethod.java"), expected);
     }
@@ -45,17 +44,16 @@ public class UnusedPrivateMethodCheckTest
             "91:18: Unused private method 'writeObject'.",
             "95:18: Unused private method 'writeObject'.",
             "99:18: Unused private method 'writeObject'.",
-            "103:17: Unused private method 'writeObject'.",
+            "103:18: Unused private method 'readObject'.",
             "107:18: Unused private method 'readObject'.",
-            "111:18: Unused private method 'readObject'.",
-            "115:18: Unused private method 'readObject'.",
-            "119:17: Unused private method 'readObject'.",
-            "123:17: Unused private method 'writeReplace'.",
-            "128:30: Unused private method 'writeReplace'.",
-            "133:20: Unused private method 'writeReplace'.",
-            "138:17: Unused private method 'readResolve'.",
+            "111:17: Unused private method 'writeReplace'.",
+            "116:20: Unused private method 'writeReplace'.",
+            "121:17: Unused private method 'readResolve'.",
+            "126:20: Unused private method 'readResolve'.",
+            "134:17: Unused private method 'writeObject'.",
+            "139:18: Unused private method 'readObject'.",
             "143:20: Unused private method 'readResolve'.",
-            "148:20: Unused private method 'readResolve'.",
+            "151:17: Unused private method 'readObject'.",
         };
         verify(checkConfig, getPath("usage/InputUnusedMethod.java"), expected);
     }
@@ -68,4 +66,13 @@ public class UnusedPrivateMethodCheckTest
        };
        verify(checkConfig, getPath("usage/InputInnerUsedMethod.java"), expected);
    }
+
+   public void testEmptyFile() throws Exception
+   {
+       final DefaultConfiguration checkConfig =
+           createCheckConfig(UnusedPrivateMethodCheck.class);
+       final String[] expected = {
+       };
+       verify(checkConfig, getPath("usage/InputEmptyFile.java"), expected);
+   }
 }
diff --git a/src/xdocs/releasenotes.xml b/src/xdocs/releasenotes.xml
index 38b79df4c..f2af60ec4 100755
--- a/src/xdocs/releasenotes.xml
+++ b/src/xdocs/releasenotes.xml
@@ -26,6 +26,9 @@
           <li>Fixed bug #1185722 (DeclarationCollector.leaveToken unbalanced
           with visitToken)</li>
 
+          <li>Fixed NPE in AbstractUsageCheck when we process an empty
+          file (bug 1165855)</li>
+
       </ul>
 
     </section>