diff --git a/forge-core/src/main/java/forge/card/CardEdition.java b/forge-core/src/main/java/forge/card/CardEdition.java
index 872187d0338..f9ce44bff7e 100644
--- a/forge-core/src/main/java/forge/card/CardEdition.java
+++ b/forge-core/src/main/java/forge/card/CardEdition.java
@@ -328,6 +328,13 @@ private CardEdition(ListMultimap<String, EditionEntry> cardMap, ListMultimap<Str
         this.cardMap = cardMap;
         this.cardsInSet = new ArrayList<>(cardMap.values());
         Collections.sort(cardsInSet);
+        this.cardsInSetLookupMap = cardsInSet.stream().collect(
+            Multimaps.toMultimap(
+                e -> e.name,
+                e -> e,
+                MultimapBuilder.treeKeys(String.CASE_INSENSITIVE_ORDER).arrayListValues()::build
+            )
+        );
         this.tokenMap = tokens;
         this.customPrintSheetsToParse = customPrintSheetsToParse;
     }
@@ -343,7 +350,6 @@ private CardEdition(ListMultimap<String, EditionEntry> cardMap, ListMultimap<Str
      *   it uses the 3-letter codes for the folder no matter the age of the set.
      * @param type the set type
      * @param name the name of the set
-     * @param cards the cards in the set
      */
     private CardEdition(String date, String code, String code2, Type type, String name, FoilType foil) {
         this(ArrayListMultimap.create(), ArrayListMultimap.create(), new HashMap<>());
@@ -409,7 +415,7 @@ public List<EditionEntry> getAllCardsInSet() {
         return cardsInSet;
     }
 
-    private ListMultimap<String, EditionEntry> cardsInSetLookupMap = null;
+    private final ListMultimap<String, EditionEntry> cardsInSetLookupMap;
 
     /**
      * Get all the CardInSet instances with the input card name.
@@ -417,17 +423,8 @@ public List<EditionEntry> getAllCardsInSet() {
      * @return A List of all the CardInSet instances for a given name.
      * If not found, an Empty sequence (view) will be returned instead!
      */
-    public List<EditionEntry> getCardInSet(String cardName){
-        if (cardsInSetLookupMap == null) {
-            // initialise
-            cardsInSetLookupMap = Multimaps.newListMultimap(new TreeMap<>(String.CASE_INSENSITIVE_ORDER), Lists::newArrayList);
-            List<EditionEntry> cardsInSet = this.getAllCardsInSet();
-            for (EditionEntry cis : cardsInSet){
-                String key = cis.name;
-                cardsInSetLookupMap.put(key, cis);
-            }
-        }
-        return this.cardsInSetLookupMap.get(cardName);
+    public List<EditionEntry> getCardInSet(String cardName) {
+        return cardsInSetLookupMap.get(cardName);
     }
 
     public EditionEntry getCardFromCollectorNumber(String collectorNumber) {