diff --git a/documentation/Makefile b/documentation/Makefile
index 8dcf9476b..23f336428 100644
--- a/documentation/Makefile
+++ b/documentation/Makefile
@@ -54,7 +54,7 @@ HTMLFILES	= \
 		subclassing.html \
 		opengl.html \
 		fluid.html \
-		advanced.hml \
+		advanced.html \
 		widgets.html \
 		Fl.html \
 		Fl_Adjuster.html \