diff --git a/pdfbox/src/main/java/org/apache/pdfbox/cos/COSArray.java b/pdfbox/src/main/java/org/apache/pdfbox/cos/COSArray.java
index d6e7db23dd3..e16874d3971 100644
--- a/pdfbox/src/main/java/org/apache/pdfbox/cos/COSArray.java
+++ b/pdfbox/src/main/java/org/apache/pdfbox/cos/COSArray.java
@@ -53,6 +53,14 @@ public COSArray()
         this(new ArrayList<>(), true);
     }
 
+    /**
+     * Constructor.
+     */
+    public COSArray(int initialCapacity)
+    {
+        this(new ArrayList<>(initialCapacity), true);
+    }
+
     /**
      * Use the given list to initialize the COSArray.
      * 
@@ -725,7 +733,7 @@ public List<Integer> toCOSNumberIntegerList()
      */
     public static COSArray ofCOSIntegers(List<Integer> integer)
     {
-        COSArray retval = new COSArray();
+        COSArray retval = new COSArray(integer.size());
         integer.forEach(s -> retval.add(COSInteger.get(s.longValue())));
         return retval;
     }
@@ -739,7 +747,7 @@ public static COSArray ofCOSIntegers(List<Integer> integer)
      */
     public static COSArray ofCOSNames(List<String> strings)
     {
-        COSArray retval = new COSArray();
+        COSArray retval = new COSArray(strings.size());
         strings.forEach(s -> retval.add(COSName.getPDFName(s)));
         return retval;
     }
@@ -753,7 +761,7 @@ public static COSArray ofCOSNames(List<String> strings)
      */
     public static COSArray ofCOSStrings(List<String> strings)
     {
-        COSArray retval = new COSArray();
+        COSArray retval = new COSArray(strings.size());
         strings.forEach(s -> retval.add(new COSString(s)));
         return retval;
     }
diff --git a/pdfbox/src/main/java/org/apache/pdfbox/multipdf/PDFCloneUtility.java b/pdfbox/src/main/java/org/apache/pdfbox/multipdf/PDFCloneUtility.java
index 9a822017642..39878cfb792 100644
--- a/pdfbox/src/main/java/org/apache/pdfbox/multipdf/PDFCloneUtility.java
+++ b/pdfbox/src/main/java/org/apache/pdfbox/multipdf/PDFCloneUtility.java
@@ -126,7 +126,7 @@ private COSBase cloneCOSBaseForNewDocument(COSBase base) throws IOException
 
     private COSArray cloneCOSArray(COSArray array) throws IOException
     {
-        COSArray newArray = new COSArray();
+        COSArray newArray = new COSArray(array.size());
         for (int i = 0; i < array.size(); i++)
         {
             COSBase value = array.get(i);
diff --git a/pdfbox/src/main/java/org/apache/pdfbox/multipdf/Splitter.java b/pdfbox/src/main/java/org/apache/pdfbox/multipdf/Splitter.java
index d8eaa936a77..a8d604e1e2f 100644
--- a/pdfbox/src/main/java/org/apache/pdfbox/multipdf/Splitter.java
+++ b/pdfbox/src/main/java/org/apache/pdfbox/multipdf/Splitter.java
@@ -313,7 +313,7 @@ private void cloneTreeElement(
             {
                 // create a clone of the array
                 COSArray srcArray = (COSArray) actualSrcObj;
-                COSArray dstArray = new COSArray();
+                COSArray dstArray = new COSArray(srcArray.size());
                 for (int i = 0; i < srcArray.size(); ++i)
                 {
                     COSBase srcElement = srcArray.getObject(i);
diff --git a/pdfbox/src/main/java/org/apache/pdfbox/pdfparser/PDFXRefStream.java b/pdfbox/src/main/java/org/apache/pdfbox/pdfparser/PDFXRefStream.java
index ffd36c078d7..5011bb3bd9f 100644
--- a/pdfbox/src/main/java/org/apache/pdfbox/pdfparser/PDFXRefStream.java
+++ b/pdfbox/src/main/java/org/apache/pdfbox/pdfparser/PDFXRefStream.java
@@ -74,7 +74,7 @@ public COSStream getStream() throws IOException
         stream.setLong(COSName.SIZE, size);
     
         List<Long> indexEntry = getIndexEntry();
-        COSArray indexAsArray = new COSArray();
+        COSArray indexAsArray = new COSArray(indexEntry.size());
         for ( Long i : indexEntry )
         {
             indexAsArray.add(COSInteger.get(i));
@@ -82,7 +82,7 @@ public COSStream getStream() throws IOException
         stream.setItem(COSName.INDEX, indexAsArray);
 
         int[] wEntry = getWEntry();
-        COSArray wAsArray = new COSArray();
+        COSArray wAsArray = new COSArray(wEntry.length);
         for (int j : wEntry)
         {
             wAsArray.add(COSInteger.get(j));
diff --git a/pdfbox/src/main/java/org/apache/pdfbox/pdmodel/PDPageTree.java b/pdfbox/src/main/java/org/apache/pdfbox/pdmodel/PDPageTree.java
index 81404e904d2..02649d27dee 100644
--- a/pdfbox/src/main/java/org/apache/pdfbox/pdmodel/PDPageTree.java
+++ b/pdfbox/src/main/java/org/apache/pdfbox/pdmodel/PDPageTree.java
@@ -86,7 +86,7 @@ public PDPageTree(COSDictionary root)
         // repair bad PDFs which contain a Page dict instead of a page tree, see PDFBOX-3154
         if (COSName.PAGE.equals(root.getCOSName(COSName.TYPE)))
         {
-            COSArray kids = new COSArray();
+            COSArray kids = new COSArray(1);
             kids.add(root);
             this.root = new COSDictionary();
             this.root.setItem(COSName.KIDS, kids);
diff --git a/pdfbox/src/main/java/org/apache/pdfbox/pdmodel/documentinterchange/taggedpdf/PDStandardAttributeObject.java b/pdfbox/src/main/java/org/apache/pdfbox/pdmodel/documentinterchange/taggedpdf/PDStandardAttributeObject.java
index ae0abf08e14..bb3fc4e7b08 100644
--- a/pdfbox/src/main/java/org/apache/pdfbox/pdmodel/documentinterchange/taggedpdf/PDStandardAttributeObject.java
+++ b/pdfbox/src/main/java/org/apache/pdfbox/pdmodel/documentinterchange/taggedpdf/PDStandardAttributeObject.java
@@ -125,7 +125,7 @@ protected String[] getArrayOfString(String name)
     protected void setArrayOfString(String name, String[] values)
     {
         COSBase oldBase = this.getCOSObject().getDictionaryObject(name);
-        COSArray array = new COSArray();
+        COSArray array = new COSArray(values.length);
         for (String value : values)
         {
             array.add(new COSString(value));
@@ -212,7 +212,7 @@ protected void setName(String name, String value)
     protected void setArrayOfName(String name, String[] values)
     {
         COSBase oldBase = this.getCOSObject().getDictionaryObject(name);
-        COSArray array = new COSArray();
+        COSArray array = new COSArray(values.length);
         for (String value : values)
         {
             array.add(COSName.getPDFName(value));
@@ -363,7 +363,7 @@ protected void setNumber(String name, int value)
      */
     protected void setArrayOfNumber(String name, float[] values)
     {
-        COSArray array = new COSArray();
+        COSArray array = new COSArray(values.length);
         for (float value : values)
         {
             array.add(new COSFloat(value));
diff --git a/pdfbox/src/main/java/org/apache/pdfbox/pdmodel/fdf/FDFAnnotation.java b/pdfbox/src/main/java/org/apache/pdfbox/pdmodel/fdf/FDFAnnotation.java
index 85a34298992..2e0b7797a56 100644
--- a/pdfbox/src/main/java/org/apache/pdfbox/pdmodel/fdf/FDFAnnotation.java
+++ b/pdfbox/src/main/java/org/apache/pdfbox/pdmodel/fdf/FDFAnnotation.java
@@ -294,7 +294,7 @@ protected FDFAnnotation(Element element) throws IOException
             if (dashes != null && !dashes.isEmpty())
             {
                 String[] dashesValues = dashes.split(",");
-                COSArray dashPattern = new COSArray();
+                COSArray dashPattern = new COSArray(dashesValues.length);
                 for (String dashesValue : dashesValues)
                 {
                     dashPattern.add(COSNumber.get(dashesValue));
diff --git a/pdfbox/src/main/java/org/apache/pdfbox/pdmodel/fdf/FDFAnnotationPolyline.java b/pdfbox/src/main/java/org/apache/pdfbox/pdmodel/fdf/FDFAnnotationPolyline.java
index 75bd91c4cc5..dcc1fbf7558 100644
--- a/pdfbox/src/main/java/org/apache/pdfbox/pdmodel/fdf/FDFAnnotationPolyline.java
+++ b/pdfbox/src/main/java/org/apache/pdfbox/pdmodel/fdf/FDFAnnotationPolyline.java
@@ -153,7 +153,7 @@ public void setStartPointEndingStyle(String style)
         COSArray array = annot.getCOSArray(COSName.LE);
         if (array == null)
         {
-            array = new COSArray();
+            array = new COSArray(2);
             array.add(COSName.getPDFName(actualStyle));
             array.add(COSName.getPDFName(PDAnnotationLine.LE_NONE));
             annot.setItem(COSName.LE, array);
@@ -186,7 +186,7 @@ public void setEndPointEndingStyle(String style)
         COSArray array = annot.getCOSArray(COSName.LE);
         if (array == null)
         {
-            array = new COSArray();
+            array = new COSArray(2);
             array.add(COSName.getPDFName(PDAnnotationLine.LE_NONE));
             array.add(COSName.getPDFName(actualStyle));
             annot.setItem(COSName.LE, array);