diff --git a/ws/Docbook/Preprocess/make.image b/ws/Docbook/Preprocess/make.image
index 45edaab1aaa6738c2c2a327c4580c52ef55a6ad5..25d31a0b9890202dfc5712c49053fdf4a1ddfc97 100644
--- a/ws/Docbook/Preprocess/make.image
+++ b/ws/Docbook/Preprocess/make.image
@@ -17,7 +17,7 @@ include mediaobjects.list
 	cd $(@D);pdf2svg $(*F).pdf $(*F).pdf.svg
 
 %.webm.mp4:%.webm
-	ffmpeg -y -i $< -vcodec libx264 -acodec aac -strict -2 -r 10 $<.mp4
+	ffmpeg -y -i $< -vcodec h264 -acodec aac -strict -2 -r 10 $<.mp4
 	ffmpeg -i $< -vframes 1 $<.png