diff --git a/cockatrice/src/carddatabase.cpp b/cockatrice/src/carddatabase.cpp
index f798b1e1..31344a8f 100644
--- a/cockatrice/src/carddatabase.cpp
+++ b/cockatrice/src/carddatabase.cpp
@@ -751,7 +751,7 @@ void CardDatabase::loadCardsFromXml(QXmlStreamReader &xml, bool tokens)
                 else if (xml.name() == "manacost")
                     manacost = xml.readElementText();
                 else if (xml.name() == "cmc")
-                    cmc = xml.readElementText().toInt();
+                    cmc = xml.readElementText();
                 else if (xml.name() == "type")
                     type = xml.readElementText();
                 else if (xml.name() == "pt")
diff --git a/cockatrice/src/cardfilter.cpp b/cockatrice/src/cardfilter.cpp
index fb59adcf..06a41ca9 100644
--- a/cockatrice/src/cardfilter.cpp
+++ b/cockatrice/src/cardfilter.cpp
@@ -31,6 +31,8 @@ const char *CardFilter::attrName(Attr a)
             return "set";
         case AttrManaCost:
             return "mana cost";
+        case AttrCmc:
+            return "cmc";
         default:
             return "";
     }
diff --git a/cockatrice/src/cardfilter.h b/cockatrice/src/cardfilter.h
index e5f88123..4b7debb2 100644
--- a/cockatrice/src/cardfilter.h
+++ b/cockatrice/src/cardfilter.h
@@ -22,6 +22,7 @@ public:
         AttrText,
         AttrSet,
         AttrManaCost,
+        AttrCmc,
         AttrEnd
     };
 
diff --git a/cockatrice/src/filtertree.cpp b/cockatrice/src/filtertree.cpp
index 5fc516f3..c33e94be 100644
--- a/cockatrice/src/filtertree.cpp
+++ b/cockatrice/src/filtertree.cpp
@@ -199,34 +199,31 @@ bool FilterItem::acceptManaCost(const CardInfo *info) const
     return (info->getManaCost() == term);
 }
 
+bool FilterItem::acceptCmc(const CardInfo *info) const
+{
+    return (info->getCmc() == term);
+}
+
 bool FilterItem::acceptCardAttr(const CardInfo *info, CardFilter::Attr attr) const
 {
-    bool status;
-
     switch (attr) {
         case CardFilter::AttrName:
-            status = acceptName(info);
-            break;
+            return acceptName(info);
         case CardFilter::AttrType:
-            status = acceptType(info);
-            break;
+            return acceptType(info);
         case CardFilter::AttrColor:
-            status = acceptColor(info);
-            break;
+            return acceptColor(info);
         case CardFilter::AttrText:
-            status = acceptText(info);
-            break;
+            return acceptText(info);
         case CardFilter::AttrSet:
-            status = acceptSet(info);
-            break;
+            return acceptSet(info);
         case CardFilter::AttrManaCost:
-            status = acceptManaCost(info);
-            break;
+            return acceptManaCost(info);
+        case CardFilter::AttrCmc:
+            return acceptCmc(info);
         default:
-            status = true; /* ignore this attribute */
+            return true; /* ignore this attribute */
     }
-
-    return status;
 }
 
 /* need to define these here to make QT happy, otherwise
diff --git a/cockatrice/src/filtertree.h b/cockatrice/src/filtertree.h
index 68f8fafb..6ee58a7e 100644
--- a/cockatrice/src/filtertree.h
+++ b/cockatrice/src/filtertree.h
@@ -117,6 +117,7 @@ public:
     bool acceptText(const CardInfo *info) const;
     bool acceptSet(const CardInfo *info) const;
     bool acceptManaCost(const CardInfo *info) const;
+    bool acceptCmc(const CardInfo *info) const;
     bool acceptCardAttr(const CardInfo *info, CardFilter::Attr attr) const;
 };
 
diff --git a/oracle/src/oracleimporter.cpp b/oracle/src/oracleimporter.cpp
index ba47b61c..f792829b 100644
--- a/oracle/src/oracleimporter.cpp
+++ b/oracle/src/oracleimporter.cpp
@@ -187,6 +187,7 @@ int OracleImporter::importTextSpoiler(CardSet *set, const QVariant &data)
                 // add first card's data
                 cardName = card1->contains("name") ? card1->value("name").toString() : QString("");
                 cardCost = card1->contains("manaCost") ? card1->value("manaCost").toString() : QString("");
+                cmc = card1->contains("cmc") ? card1->value("cmc").toString() : QString("");
                 cardType = card1->contains("type") ? card1->value("type").toString() : QString("");
                 cardPT = card1->contains("power") || card1->contains("toughness") ? card1->value("power").toString() + QString('/') + card1->value("toughness").toString() : QString("");
                 cardText = card1->contains("text") ? card1->value("text").toString() : QString("");
@@ -199,8 +200,10 @@ int OracleImporter::importTextSpoiler(CardSet *set, const QVariant &data)
                 cardPT += card2->contains("power") || card2->contains("toughness") ? QString(" // ") + card2->value("power").toString() + QString('/') + card2->value("toughness").toString() : QString("");
                 cardText += card2->contains("text") ? QString("\n\n---\n\n") + card2->value("text").toString() : QString("");
             } else {
-                // first card od a pair; enqueue for later merging
-                splitCards.insert(cardId, map);
+                // first card of a pair; enqueue for later merging
+                // Conditional on cardId because promo prints have no muid - see #640
+                if (cardId)
+                  splitCards.insert(cardId, map);
                 continue;
             }
         } else {