diff --git a/src/java/org/apache/poi/hssf/usermodel/HSSFWorkbook.java b/src/java/org/apache/poi/hssf/usermodel/HSSFWorkbook.java
index e25c7b9e70..4b041ef17a 100644
--- a/src/java/org/apache/poi/hssf/usermodel/HSSFWorkbook.java
+++ b/src/java/org/apache/poi/hssf/usermodel/HSSFWorkbook.java
@@ -34,11 +34,13 @@ import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.Hashtable;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 import java.util.NoSuchElementException;
+import java.util.Set;
 import java.util.regex.Pattern;
 
 import org.apache.commons.codec.digest.DigestUtils;
@@ -542,27 +544,40 @@ public final class HSSFWorkbook extends POIDocument implements org.apache.poi.ss
     /**
      * Selects multiple sheets as a group. This is distinct from
      * the 'active' sheet (which is the sheet with focus).
+     * Unselects sheets that are not in <code>indexes</code>.
      *
      * @param indexes
      */
     public void setSelectedTabs(int[] indexes) {
+        Collection<Integer> list = new ArrayList<Integer>(indexes.length);
+        for (int index : indexes) {
+            list.add(index);
+        }
+        setSelectedTabs(list);
+    }
+    
+    /**
+     * Selects multiple sheets as a group. This is distinct from
+     * the 'active' sheet (which is the sheet with focus).
+     * Unselects sheets that are not in <code>indexes</code>.
+     *
+     * @param indexes
+     */
+    public void setSelectedTabs(Collection<Integer> indexes) {
 
         for (int index : indexes) {
             validateSheetIndex(index);
         }
+        // ignore duplicates
+        Set<Integer> set = new HashSet<Integer>(indexes);
         int nSheets = _sheets.size();
         for (int i=0; i<nSheets; i++) {
-            boolean bSelect = false;
-            for (int index : indexes) {
-                if (index == i) {
-                    bSelect = true;
-                    break;
-                }
-
-            }
-               getSheetAt(i).setSelected(bSelect);
+            boolean bSelect = set.contains(i);
+            getSheetAt(i).setSelected(bSelect);
         }
-        workbook.getWindowOne().setNumSelectedTabs((short)indexes.length);
+        // this is true only if all values in set were valid sheet indexes (between 0 and nSheets-1, inclusive)
+        short nSelected = (short) set.size();
+        workbook.getWindowOne().setNumSelectedTabs(nSelected);
     }
     
     /**
diff --git a/src/testcases/org/apache/poi/hssf/usermodel/TestHSSFWorkbook.java b/src/testcases/org/apache/poi/hssf/usermodel/TestHSSFWorkbook.java
index d8fcf6bcca..04527f286f 100644
--- a/src/testcases/org/apache/poi/hssf/usermodel/TestHSSFWorkbook.java
+++ b/src/testcases/org/apache/poi/hssf/usermodel/TestHSSFWorkbook.java
@@ -33,6 +33,10 @@ import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
 import java.util.List;
 
 import org.apache.poi.POIDataSamples;
@@ -210,50 +214,70 @@ public final class TestHSSFWorkbook extends BaseTestWorkbook {
         
         wb.close();
     }
+    
+    private static List<Integer> arrayToList(int[] array) {
+        List<Integer> list = new ArrayList<Integer>(array.length);
+        for ( Integer element : array ) {
+            list.add(element);
+        }
+        return list;
+    }
+    
+    private static void assertCollectionsEquals(Collection<Integer> expected, Collection<Integer> actual) {
+        assertEquals("size", expected.size(), actual.size());
+        for (int e : expected) {
+            assertTrue(actual.contains(e));
+        }
+        for (int a : actual) {
+            assertTrue(expected.contains(a));
+        }
+    }
 
     @Test
     public void selectMultiple() throws IOException {
-        HSSFWorkbook wb=new HSSFWorkbook();
+        HSSFWorkbook wb = new HSSFWorkbook();
+        HSSFSheet sheet0 = wb.createSheet("Sheet0");
         HSSFSheet sheet1 = wb.createSheet("Sheet1");
         HSSFSheet sheet2 = wb.createSheet("Sheet2");
         HSSFSheet sheet3 = wb.createSheet("Sheet3");
         HSSFSheet sheet4 = wb.createSheet("Sheet4");
         HSSFSheet sheet5 = wb.createSheet("Sheet5");
-        HSSFSheet sheet6 = wb.createSheet("Sheet6");
 
-        wb.setSelectedTabs(new int[] { 0, 2, 3});
+        
+        List<Integer> selected = arrayToList(new int[] { 0, 2, 3 });
+        wb.setSelectedTabs(selected);
 
+        assertCollectionsEquals(selected, wb.getSelectedTabs());
+        assertEquals(true, sheet0.isSelected());
+        assertEquals(false, sheet1.isSelected());
+        assertEquals(true, sheet2.isSelected());
+        assertEquals(true, sheet3.isSelected());
+        assertEquals(false, sheet4.isSelected());
+        assertEquals(false, sheet5.isSelected());
+
+        selected = arrayToList(new int[] { 1, 3, 5 });
+        wb.setSelectedTabs(selected);
+
+        // previous selection should be cleared
+        assertCollectionsEquals(selected, wb.getSelectedTabs());
+        assertEquals(false, sheet0.isSelected());
         assertEquals(true, sheet1.isSelected());
         assertEquals(false, sheet2.isSelected());
         assertEquals(true, sheet3.isSelected());
-        assertEquals(true, sheet4.isSelected());
-        assertEquals(false, sheet5.isSelected());
-        assertEquals(false, sheet6.isSelected());
+        assertEquals(false, sheet4.isSelected());
+        assertEquals(true, sheet5.isSelected());
 
-        wb.setSelectedTabs(new int[] { 1, 3, 5});
-
-        assertEquals(false, sheet1.isSelected());
-        assertEquals(true, sheet2.isSelected());
-        assertEquals(false, sheet3.isSelected());
-        assertEquals(true, sheet4.isSelected());
-        assertEquals(false, sheet5.isSelected());
-        assertEquals(true, sheet6.isSelected());
-
-        assertEquals(true, sheet1.isActive());
+        assertEquals(true, sheet0.isActive());
         assertEquals(false, sheet2.isActive());
-
-
-        assertEquals(true, sheet1.isActive());
-        assertEquals(false, sheet3.isActive());
         wb.setActiveSheet(2);
-        assertEquals(false, sheet1.isActive());
-        assertEquals(true, sheet3.isActive());
+        assertEquals(false, sheet0.isActive());
+        assertEquals(true, sheet2.isActive());
 
         /*{ // helpful if viewing this workbook in excel:
+            sheet0.createRow(0).createCell(0).setCellValue(new HSSFRichTextString("Sheet0"));
             sheet1.createRow(0).createCell(0).setCellValue(new HSSFRichTextString("Sheet1"));
             sheet2.createRow(0).createCell(0).setCellValue(new HSSFRichTextString("Sheet2"));
             sheet3.createRow(0).createCell(0).setCellValue(new HSSFRichTextString("Sheet3"));
-            sheet4.createRow(0).createCell(0).setCellValue(new HSSFRichTextString("Sheet4"));
 
             try {
                 File fOut = TempFile.createTempFile("sheetMultiSelect", ".xls");