diff --git a/content/content.c b/content/content.c
index a04051bda..869750100 100644
--- a/content/content.c
+++ b/content/content.c
@@ -96,6 +96,7 @@ nserror content__init(struct content *c, const content_handler *handler,
 	c->width = 0;
 	c->height = 0;
 	c->available_width = 0;
+	c->available_height = 0;
 	c->quirks = quirks;
 	c->refresh = 0;
 	nsu_getmonotonic_ms(&c->time);
@@ -355,6 +356,7 @@ void content__reformat(struct content *c, bool background,
 	assert(c->locked == false);
 
 	c->available_width = width;
+	c->available_height = height;
 	if (c->handler->reformat != NULL) {
 
 		c->locked = true;
diff --git a/content/content_protected.h b/content/content_protected.h
index 21b73a662..be277a042 100644
--- a/content/content_protected.h
+++ b/content/content_protected.h
@@ -113,7 +113,8 @@ struct content {
 	content_status status;	/**< Current status. */
 
 	int width, height;	/**< Dimensions, if applicable. */
-	int available_width;	/**< Available width (eg window width). */
+	int available_width;	/**< Viewport width. */
+	int available_height;	/**< Viewport height. */
 
 	bool quirks;		/**< Content is in quirks mode */
 	char *fallback_charset;	/**< Fallback charset, or NULL */