diff --git a/src/checkstyle/com/puppycrawl/tools/checkstyle/checks/duplicates/StrictDuplicateCodeCheck.java b/src/checkstyle/com/puppycrawl/tools/checkstyle/checks/duplicates/StrictDuplicateCodeCheck.java
index 72928954c..11c11ca9b 100644
--- a/src/checkstyle/com/puppycrawl/tools/checkstyle/checks/duplicates/StrictDuplicateCodeCheck.java
+++ b/src/checkstyle/com/puppycrawl/tools/checkstyle/checks/duplicates/StrictDuplicateCodeCheck.java
@@ -191,7 +191,7 @@ public final class StrictDuplicateCodeCheck extends AbstractFileSetCheck
         long start = System.currentTimeMillis();
         mLoc = 0;
         mDuplicates = 0;
-        mFiles = aFiles;
+        mFiles = filter(aFiles);
         mLineChecksums = new long[mFiles.length][];
         mSortedRelevantChecksums = new long[mFiles.length][];
 
@@ -199,7 +199,7 @@ public final class StrictDuplicateCodeCheck extends AbstractFileSetCheck
             LOG.debug("Reading input files");
         }
 
-        for (int i = 0; i < aFiles.length; i++) {
+        for (int i = 0; i < mFiles.length; i++) {
             try {
                 File file = mFiles[i];
                 String[] lines = Utils.getLines(file.getPath());
diff --git a/src/checkstyle/com/puppycrawl/tools/checkstyle/checkstyle_packages.xml b/src/checkstyle/com/puppycrawl/tools/checkstyle/checkstyle_packages.xml
index a8d7fd5c6..b60e61d04 100644
--- a/src/checkstyle/com/puppycrawl/tools/checkstyle/checkstyle_packages.xml
+++ b/src/checkstyle/com/puppycrawl/tools/checkstyle/checkstyle_packages.xml
@@ -10,6 +10,7 @@
       <package name="blocks"/>
       <package name="coding"/>
       <package name="design"/>
+      <package name="duplicates"/>
       <package name="imports"/>
       <package name="indentation"/>
       <package name="j2ee"/>
diff --git a/src/tests/com/puppycrawl/tools/checkstyle/PackageNamesLoaderTest.java b/src/tests/com/puppycrawl/tools/checkstyle/PackageNamesLoaderTest.java
index 6263f6691..0d0aa45a6 100644
--- a/src/tests/com/puppycrawl/tools/checkstyle/PackageNamesLoaderTest.java
+++ b/src/tests/com/puppycrawl/tools/checkstyle/PackageNamesLoaderTest.java
@@ -55,6 +55,7 @@ public class PackageNamesLoaderTest extends TestCase
             "com.puppycrawl.tools.checkstyle.checks.blocks.",
             "com.puppycrawl.tools.checkstyle.checks.coding.",
             "com.puppycrawl.tools.checkstyle.checks.design.",
+            "com.puppycrawl.tools.checkstyle.checks.duplicates.",
             "com.puppycrawl.tools.checkstyle.checks.imports.",
             "com.puppycrawl.tools.checkstyle.checks.indentation.",
             "com.puppycrawl.tools.checkstyle.checks.j2ee.",