diff --git a/builder/dockerfile.alpine_321.apk.build b/builder/dockerfile.alpine_321.apk.build
index 2bc1af0..6f41bde 100644
--- a/builder/dockerfile.alpine_321.apk.build
+++ b/builder/dockerfile.alpine_321.apk.build
@@ -1,7 +1,7 @@
 FROM alpine:3.21
 
 RUN apk add shadow bash
-RUN apk add abuild sudo less
+RUN apk add abuild sudo less ffmpeg-dev
 
 ENV HOME /src/alpine
 WORKDIR $HOME/kasmvncserver