diff --git a/src/core/imageexport.cpp b/src/core/imageexport.cpp
index a4994d85..b57c6dd9 100644
--- a/src/core/imageexport.cpp
+++ b/src/core/imageexport.cpp
@@ -62,6 +62,12 @@ unsigned long crc(QByteArray buf, int len)
 // images in porymap, we can effectively avoid that issue.
 void exportIndexed4BPPPng(QImage image, QString filepath)
 {
+    // Verify that the image is not empty
+    if (image.isNull()) {
+        logError(QString("Failed to export %1: the image is null.").arg(filepath));
+        return;
+    }
+
     // Header
     QByteArray pngHeader;
     pngHeader.append(static_cast<char>(0x89));
diff --git a/src/ui/tileseteditortileselector.cpp b/src/ui/tileseteditortileselector.cpp
index 1c0bd9dd..9e22401e 100644
--- a/src/ui/tileseteditortileselector.cpp
+++ b/src/ui/tileseteditortileselector.cpp
@@ -200,7 +200,7 @@ QImage TilesetEditorTileSelector::buildPrimaryTilesIndexedImage() {
     }
 
     int primaryLength = this->primaryTileset->tiles->length();
-    int height = primaryLength / this->numTilesWide;
+    int height = primaryLength / this->numTilesWide + 1;
     QImage image(this->numTilesWide * 8, height * 8, QImage::Format_RGBA8888);
 
     QPainter painter(&image);
@@ -236,7 +236,7 @@ QImage TilesetEditorTileSelector::buildSecondaryTilesIndexedImage() {
     }
 
     int secondaryLength = this->secondaryTileset->tiles->length();
-    int height = secondaryLength / this->numTilesWide;
+    int height = secondaryLength / this->numTilesWide + 1;
     QImage image(this->numTilesWide * 8, height * 8, QImage::Format_RGBA8888);
 
     QPainter painter(&image);