diff --git a/cockatrice/src/carddatabase.cpp b/cockatrice/src/carddatabase.cpp
index 5a942b0f..1677cf69 100644
--- a/cockatrice/src/carddatabase.cpp
+++ b/cockatrice/src/carddatabase.cpp
@@ -275,7 +275,7 @@ CardInfo::CardInfo(CardDatabase *_db,
                    bool _cipt,
                    int _tableRow,
                    const SetList &_sets,
-                   QMap<QString, int> _muIds)
+                   MuidMap _muIds)
     : db(_db),
       name(_name),
       isToken(_isToken),
@@ -610,7 +610,7 @@ void CardDatabase::loadCardsFromXml(QXmlStreamReader &xml)
         if (xml.name() == "card") {
             QString name, manacost, type, pt, text;
             QStringList colors;
-            QMap<QString, int> muids;
+            MuidMap muids;
             SetList sets;
             int tableRow = 0;
             int loyalty = 0;
diff --git a/cockatrice/src/carddatabase.h b/cockatrice/src/carddatabase.h
index 70d77bca..28d56d13 100644
--- a/cockatrice/src/carddatabase.h
+++ b/cockatrice/src/carddatabase.h
@@ -20,6 +20,9 @@ class QNetworkRequest;
 
 typedef QMap<QString, QString> QStringMap;
 
+// If we don't typedef this, CardInfo::CardInfo will refuse to compile on OS X.
+typedef QMap<QString, int> MuidMap;
+
 class CardSet : public QList<CardInfo *> {
 private:
     QString shortName, longName;
@@ -100,7 +103,7 @@ private:
     QString text;
     QStringList colors;
     int loyalty;
-    QMap<QString, int> muIds;
+    MuidMap muIds;
     bool cipt;
     int tableRow;
     QPixmap *pixmap;
@@ -118,7 +121,7 @@ public:
         bool _cipt = false,
         int _tableRow = 0,
         const SetList &_sets = SetList(),
-        QMap<QString, int> muids = QMap<QString, int>());
+        MuidMap muids = MuidMap());
     ~CardInfo();
     const QString &getName() const { return name; }
     bool getIsToken() const { return isToken; }