diff --git a/Dockerfile.m4 b/Dockerfile.m4
index f19debd..d5542d9 100644
--- a/Dockerfile.m4
+++ b/Dockerfile.m4
@@ -205,7 +205,7 @@ RUN make deb
 RUN dpkg -i ./turbovnc_*.deb
 
 # Build xrdp
-ARG XRDP_TREEISH=v0.9.20
+ARG XRDP_TREEISH=v0.9.21
 ARG XRDP_REMOTE=https://github.com/neutrinolabs/xrdp.git
 RUN mkdir /tmp/xrdp/
 WORKDIR /tmp/xrdp/