diff --git a/imagescrollareagl.cpp b/imagescrollareagl.cpp
index 81e6572..e77c641 100644
--- a/imagescrollareagl.cpp
+++ b/imagescrollareagl.cpp
@@ -379,7 +379,7 @@ void ImageWidget::paintGL()
         int start = std::max((int)(m_dy / THUMB_SIZE_BORDER_Y * w - w), 0);
         int end = std::min((int)(m_dy + m_height) / THUMB_SIZE_BORDER_Y * w + w, m_thumbnailCount);
 
-        fx->glDrawArraysInstanced(GL_TRIANGLE_STRIP, start*4, 4, (end - start) * 4);
+        fx->glDrawArraysInstanced(GL_TRIANGLE_STRIP, 0, 4, m_thumbnailCount);
         m_vaoThumb->release();
 
         QPainter painter(this);