diff --git a/cockatrice/src/deckview.cpp b/cockatrice/src/deckview.cpp
index 252d655c3..4c1b83b34 100644
--- a/cockatrice/src/deckview.cpp
+++ b/cockatrice/src/deckview.cpp
@@ -334,12 +334,14 @@ void DeckViewScene::rebuildTree()
 {
     clearContents();
 
-    if (!deck)
+    if (!deck) {
         return;
+    }
 
+    unsigned int cardsRenderedAlready = 0;
     InnerDecklistNode *listRoot = deck->getRoot();
-    for (int i = 0; i < listRoot->size(); i++) {
-        InnerDecklistNode *currentZone = dynamic_cast<InnerDecklistNode *>(listRoot->at(i));
+    for (const auto innerDecklistNode : *listRoot) {
+        auto *currentZone = dynamic_cast<InnerDecklistNode *>(innerDecklistNode);
 
         DeckViewCardContainer *container = cardContainers.value(currentZone->getName(), 0);
         if (!container) {
@@ -349,12 +351,15 @@ void DeckViewScene::rebuildTree()
         }
 
         for (int j = 0; j < currentZone->size(); j++) {
-            DecklistCardNode *currentCard = dynamic_cast<DecklistCardNode *>(currentZone->at(j));
+            auto *currentCard = dynamic_cast<DecklistCardNode *>(currentZone->at(j));
             if (!currentCard)
                 continue;
 
             for (int k = 0; k < currentCard->getNumber(); ++k) {
-                DeckViewCard *newCard = new DeckViewCard(currentCard->getName(), currentZone->getName(), container);
+                if (++cardsRenderedAlready >= MAX_CARDS_TO_RENDER) {
+                    break; // We can't render anymore cards efficiently, evict early
+                }
+                auto *newCard = new DeckViewCard(currentCard->getName(), currentZone->getName(), container);
                 container->addCard(newCard);
                 emit newCardAdded(newCard);
             }
diff --git a/cockatrice/src/deckview.h b/cockatrice/src/deckview.h
index 8aab1dc25..1f5b7bdee 100644
--- a/cockatrice/src/deckview.h
+++ b/cockatrice/src/deckview.h
@@ -104,6 +104,7 @@ signals:
     void sideboardPlanChanged();
 
 private:
+    static constexpr unsigned int MAX_CARDS_TO_RENDER = 300;
     bool locked;
     DeckList *deck;
     QMap<QString, DeckViewCardContainer *> cardContainers;
diff --git a/common/decklist.cpp b/common/decklist.cpp
index 1e118d22c..9620c8b7b 100644
--- a/common/decklist.cpp
+++ b/common/decklist.cpp
@@ -804,13 +804,18 @@ void DeckList::updateDeckHash()
     hashZones << DECK_ZONE_MAIN << DECK_ZONE_SIDE; // Zones in deck to be included in hashing process
     optionalZones << DECK_ZONE_TOKENS;             // Optional zones in deck not included in hashing process
 
-    for (int i = 0; i < root->size(); i++) {
-        auto *node = dynamic_cast<InnerDecklistNode *>(root->at(i));
+    unsigned int cardsHashedAlready = 0;
+    for (auto innerDecklistNode : *root) {
+        auto *node = dynamic_cast<InnerDecklistNode *>(innerDecklistNode);
         for (int j = 0; j < node->size(); j++) {
             if (hashZones.contains(node->getName())) // Mainboard or Sideboard
             {
                 auto *card = dynamic_cast<DecklistCardNode *>(node->at(j));
                 for (int k = 0; k < card->getNumber(); ++k) {
+                    if (++cardsHashedAlready >= MAX_CARDS_TO_HASH) {
+                        cardList.clear();
+                        break; // We can't efficiently calculate a hash with a larger number
+                    }
                     cardList.append((node->getName() == DECK_ZONE_SIDE ? "SB:" : "") + card->getName().toLower());
                 }
             }
diff --git a/common/decklist.h b/common/decklist.h
index bacba0ce6..6ded2d49a 100644
--- a/common/decklist.h
+++ b/common/decklist.h
@@ -173,6 +173,7 @@ class DeckList : public QObject
 {
     Q_OBJECT
 private:
+    static constexpr unsigned int MAX_CARDS_TO_HASH = 100000;
     QString name, comments;
     QString deckHash;
     QMap<QString, SideboardPlan *> sideboardPlans;