diff --git a/Dockerfile b/Dockerfile
index 800607b..ea4b2e0 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -49,8 +49,6 @@ WORKDIR /home/cmbuild/android
 VOLUME /home/cmbuild/android
 VOLUME /srv/ccache
 
-RUN CCACHE_DIR=/srv/ccache ccache -M 50G
-
 CMD /root/startup.sh
 
 # This does not work yet, see https://github.com/docker/docker/issues/9806
diff --git a/startup.sh b/startup.sh
index b93f581..4f6d817 100644
--- a/startup.sh
+++ b/startup.sh
@@ -1,5 +1,10 @@
 #!/bin/sh
 
+# Initialize ccache if needed
+if [ ! -f /srv/ccache/CACHEDIR.TAG ]; then
+	CCACHE_DIR=/srv/ccache ccache -M 50G
+fi
+
 # Fix console permissions as long as https://github.com/docker/docker/issues/9806 is not fixed
 usermod --groups tty --append cmbuild
 chgrp tty /dev/console