diff --git a/include/core/blockdata.h b/include/core/blockdata.h
index 0bb6a7b6..35c071fb 100644
--- a/include/core/blockdata.h
+++ b/include/core/blockdata.h
@@ -5,6 +5,7 @@
 
 #include <QObject>
 #include <QByteArray>
+#include <QVector>
 
 class Blockdata : public QObject
 {
@@ -16,7 +17,7 @@ public:
     }
 
 public:
-    QList<Block> *blocks = nullptr;
+    QVector<Block> *blocks = nullptr;
     void addBlock(uint16_t);
     void addBlock(Block);
     QByteArray serialize();
diff --git a/src/core/block.cpp b/src/core/block.cpp
index c064399a..bc65c923 100644
--- a/src/core/block.cpp
+++ b/src/core/block.cpp
@@ -1,6 +1,6 @@
 #include "block.h"
 
-Block::Block() {
+Block::Block() : tile(0), collision(0), elevation(0) {
 }
 
 Block::Block(uint16_t word)
diff --git a/src/core/blockdata.cpp b/src/core/blockdata.cpp
index 34aff306..77239add 100644
--- a/src/core/blockdata.cpp
+++ b/src/core/blockdata.cpp
@@ -2,7 +2,7 @@
 
 Blockdata::Blockdata(QObject *parent) : QObject(parent)
 {
-    blocks = new QList<Block>;
+    blocks = new QVector<Block>;
 }
 
 void Blockdata::addBlock(uint16_t word) {
diff --git a/src/project.cpp b/src/project.cpp
index 88c97c19..34be984e 100644
--- a/src/project.cpp
+++ b/src/project.cpp
@@ -775,6 +775,15 @@ void Project::loadBlockdata(Map* map) {
 
     QString path = QString("%1/%2").arg(root).arg(map->layout->blockdata_path);
     map->layout->blockdata = readBlockdata(path);
+
+    if (map->layout->blockdata->blocks->count() != map->getWidth() * map->getHeight()) {
+        logWarn(QString("Layout blockdata length %1 does not match dimensions %2x%3 (should be %4). Resizing blockdata.")
+                .arg(map->layout->blockdata->blocks->count())
+                .arg(map->getWidth())
+                .arg(map->getHeight())
+                .arg(map->getWidth() * map->getHeight()));
+        map->layout->blockdata->blocks->resize(map->getWidth() * map->getHeight());
+    }
 }
 
 void Project::setNewMapBlockdata(Map* map) {
diff --git a/src/ui/bordermetatilespixmapitem.cpp b/src/ui/bordermetatilespixmapitem.cpp
index 4886e42e..2093eabe 100644
--- a/src/ui/bordermetatilespixmapitem.cpp
+++ b/src/ui/bordermetatilespixmapitem.cpp
@@ -24,7 +24,7 @@ void BorderMetatilesPixmapItem::mousePressEvent(QGraphicsSceneMouseEvent *event)
 void BorderMetatilesPixmapItem::draw() {
     QImage image(32, 32, QImage::Format_RGBA8888);
     QPainter painter(&image);
-    QList<Block> *blocks = map->layout->border->blocks;
+    QVector<Block> *blocks = map->layout->border->blocks;
 
     for (int i = 0; i < 2; i++) {
         for (int j = 0; j < 2; j++) {