diff --git a/oracle/src/oracleimporter.cpp b/oracle/src/oracleimporter.cpp
index 845a10ea4..7138f80af 100644
--- a/oracle/src/oracleimporter.cpp
+++ b/oracle/src/oracleimporter.cpp
@@ -12,7 +12,7 @@
 SplitCardPart::SplitCardPart(const QString &_name,
                              const QString &_text,
                              const QVariantHash &_properties,
-                             const CardInfoPerSet _setInfo)
+                             const CardInfoPerSet &_setInfo)
     : name(_name), text(_text), properties(_properties), setInfo(_setInfo)
 {
 }
@@ -125,11 +125,11 @@ static void sortAndReduceColors(QString &colors)
 }
 
 CardInfoPtr OracleImporter::addCard(QString name,
-                                    QString text,
+                                    const QString &text,
                                     bool isToken,
                                     QVariantHash properties,
-                                    QList<CardRelation *> &relatedCards,
-                                    CardInfoPerSet setInfo)
+                                    const QList<CardRelation *> &relatedCards,
+                                    const CardInfoPerSet &setInfo)
 {
     // Workaround for card name weirdness
     name = name.replace("Æ", "AE");
diff --git a/oracle/src/oracleimporter.h b/oracle/src/oracleimporter.h
index 8232df259..d7f436577 100644
--- a/oracle/src/oracleimporter.h
+++ b/oracle/src/oracleimporter.h
@@ -92,7 +92,8 @@ public:
 class SplitCardPart
 {
 public:
-    SplitCardPart(const QString &_name, const QString &_text, const QVariantHash &_properties, CardInfoPerSet setInfo);
+    SplitCardPart(const QString &_name, const QString &_text, const QVariantHash &_properties,
+                  const CardInfoPerSet &setInfo);
     inline const QString &getName() const
     {
         return name;
@@ -136,11 +137,11 @@ private:
     QList<SetToDownload> allSets;
 
     CardInfoPtr addCard(QString name,
-                        QString text,
+                        const QString &text,
                         bool isToken,
                         QVariantHash properties,
-                        QList<CardRelation *> &relatedCards,
-                        CardInfoPerSet setInfo);
+                        const QList<CardRelation *> &relatedCards,
+                        const CardInfoPerSet &setInfo);
 signals:
     void setIndexChanged(int cardsImported, int setIndex, const QString &setName);
     void dataReadProgress(int bytesRead, int totalBytes);