diff --git a/card.js b/card.js
index 0c0a608..dca1639 100644
--- a/card.js
+++ b/card.js
@@ -99,4 +99,17 @@
   MemoryGame.Card.prototype = Object.create(EventDispatcher.prototype);
   MemoryGame.Card.prototype.constructor = MemoryGame.Card;
 
+  /**
+   * Check to see if the given object corresponds with the semantics for
+   * a memory game card.
+   *
+   * @param {object} params
+   * @returns {boolean}
+   */
+  MemoryGame.Card.isValid = function (params) {
+    return (params !== undefined &&
+            params.image !== undefined &&
+            params.image.path !== undefined);
+  };
+
 })(H5P.MemoryGame, H5P.EventDispatcher, H5P.jQuery);
diff --git a/library.json b/library.json
index 158341f..a831a73 100644
--- a/library.json
+++ b/library.json
@@ -3,7 +3,7 @@
   "description": "See how many cards you can remember!",
   "majorVersion": 1,
   "minorVersion": 1,
-  "patchVersion": 6,
+  "patchVersion": 8,
   "runnable": 1,
   "author": "Amendor AS",
   "license": "MIT",
@@ -30,4 +30,4 @@
       "path": "popup.js"
     }
   ]
-}
\ No newline at end of file
+}
diff --git a/memory-game.js b/memory-game.js
index 6ca5e48..845fe3b 100644
--- a/memory-game.js
+++ b/memory-game.js
@@ -103,11 +103,13 @@ H5P.MemoryGame = (function (EventDispatcher, $) {
 
     // Initialize cards.
     for (var i = 0; i < parameters.cards.length; i++) {
-      // Add two of each card
-      var cardOne = new MemoryGame.Card(parameters.cards[i], id);
-      var cardTwo = new MemoryGame.Card(parameters.cards[i], id);
-      addCard(cardOne, cardTwo);
-      addCard(cardTwo, cardOne);
+      if (MemoryGame.Card.isValid(parameters.cards[i])) {
+        // Add two of each card
+        var cardOne = new MemoryGame.Card(parameters.cards[i], id);
+        var cardTwo = new MemoryGame.Card(parameters.cards[i], id);
+        addCard(cardOne, cardTwo);
+        addCard(cardTwo, cardOne);
+      }
     }
     H5P.shuffleArray(cards);