diff --git a/2023/src/main/java/nl/e86/aoc/aoc2023/day04/Pile.java b/2023/src/main/java/nl/e86/aoc/aoc2023/day04/Pile.java
index 52a0125..0e2c598 100644
--- a/2023/src/main/java/nl/e86/aoc/aoc2023/day04/Pile.java
+++ b/2023/src/main/java/nl/e86/aoc/aoc2023/day04/Pile.java
@@ -13,7 +13,7 @@ public int getSolutionPt1() {
         return getScore();
     }
     public int getSolutionPt2() {
-        return -1;
+        return winCards();
     }
 
     private int getScore() {
@@ -24,6 +24,34 @@ private int getScore() {
         return score;
     }
 
+    private int winCards() {
+        int totalCards = 0;
+        int cardIndex = 0;
+        while (cardIndex < cards.size()) {
+            ScratchCard currentCard = cards.get(cardIndex);
+            totalCards++;
+            int extraCards = currentCard.getExtraCards();
+            for (int i = 1; i <= extraCards; ++i) {
+                ScratchCard extraCard = duplicateCard(currentCard.getCardNumber() + i);
+                cards.add(extraCard);
+            }
+            cardIndex++;
+        }
+        return totalCards;
+    }
+
+    private ScratchCard duplicateCard(int cardId) {
+        ScratchCard match = null;
+        for (ScratchCard card : cards) {
+            if (card.getCardNumber() == cardId) {
+                match = card.getCopy();
+                break;
+            }
+        }
+
+        return match;
+    }
+
     public static Pile createFromInput(List<String> input) {
         List<ScratchCard> cards = new ArrayList<>();
         for (String inputLine : input) {
diff --git a/2023/src/main/java/nl/e86/aoc/aoc2023/day04/ScratchCard.java b/2023/src/main/java/nl/e86/aoc/aoc2023/day04/ScratchCard.java
index f897bef..0cf2aae 100644
--- a/2023/src/main/java/nl/e86/aoc/aoc2023/day04/ScratchCard.java
+++ b/2023/src/main/java/nl/e86/aoc/aoc2023/day04/ScratchCard.java
@@ -10,16 +10,20 @@ public class ScratchCard {
     private static final Pattern CARD_NUMBER_PATTERN = Pattern.compile("Card\\s*(\\d+):");
     private static final Pattern WINNING_NUMBERS_PATTERN = Pattern.compile(":(.*)\\|");
     private static final Pattern NUMBERS_ON_CARD_PATTERN = Pattern.compile("\\|(.*)$");
-    private final Integer cardNumber;
+    private final int cardNumber;
     private final List<Integer> winningNumbers;
     private final List<Integer> numbersOnCard;
 
-    private ScratchCard(Integer cardNumber, List<Integer> winningNumbers, List<Integer> numbersOnCard) {
+    private ScratchCard(int cardNumber, List<Integer> winningNumbers, List<Integer> numbersOnCard) {
         this.cardNumber = cardNumber;
         this.winningNumbers = Collections.unmodifiableList(winningNumbers);
         this.numbersOnCard = Collections.unmodifiableList(numbersOnCard);
     }
 
+    public int getCardNumber() {
+        return cardNumber;
+    }
+
     public int getScore() {
         int score = 0;
         for (Integer number : numbersOnCard) {
@@ -34,10 +38,24 @@ public int getScore() {
         return score;
     }
 
+    public int getExtraCards() {
+        int extraCards = 0;
+        for (Integer number : numbersOnCard) {
+            if (winningNumbers.contains(number)) {
+                extraCards++;
+            }
+        }
+        return extraCards;
+    }
+
+    public ScratchCard getCopy() {
+        return new ScratchCard(cardNumber, winningNumbers, numbersOnCard);
+    }
+
     public static ScratchCard createCardFromInputData(String input) {
         Matcher cardNumberMatcher = CARD_NUMBER_PATTERN.matcher(input);
         cardNumberMatcher.find();
-        Integer cardNumber = Integer.parseInt(cardNumberMatcher.group(1));
+        int cardNumber = Integer.parseInt(cardNumberMatcher.group(1));
 
         Matcher winningNumbersMatcher = WINNING_NUMBERS_PATTERN.matcher(input);
         winningNumbersMatcher.find();
diff --git a/2023/src/test/java/nl/e86/aoc/aoc2023/day04/Day04Test.java b/2023/src/test/java/nl/e86/aoc/aoc2023/day04/Day04Test.java
index fe6ed21..fdee38a 100644
--- a/2023/src/test/java/nl/e86/aoc/aoc2023/day04/Day04Test.java
+++ b/2023/src/test/java/nl/e86/aoc/aoc2023/day04/Day04Test.java
@@ -10,5 +10,9 @@ public void testDay04_1() {
         Assert.assertEquals(13, output);
     }
 
-
+    @Test
+    public void testDay04_2() {
+        int output = Day04.calculatePart2("day04.1.input");
+        Assert.assertEquals(30, output);
+    }
 }