diff --git a/apps/openmw/mwgui/bookpage.cpp b/apps/openmw/mwgui/bookpage.cpp
index c5c4e8d03..4cede0e18 100644
--- a/apps/openmw/mwgui/bookpage.cpp
+++ b/apps/openmw/mwgui/bookpage.cpp
@@ -1050,7 +1050,7 @@ public:
 
             mActiveTextFormats.clear ();
 
-            if (newBook != NULL)
+            if (newBook != nullptr)
             {
                 createActiveFormats (newBook);