diff --git a/firefox/Dockerfile b/firefox/Dockerfile
index 8a4e519..591d67b 100644
--- a/firefox/Dockerfile
+++ b/firefox/Dockerfile
@@ -8,14 +8,14 @@ RUN apt-get update && apt-get install -y \
 	&& apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 0AB215679C571D1C8325275B9BDB3D89CE49EC21 \
 	&& echo "deb http://ppa.launchpad.net/mozillateam/firefox-next/ubuntu xenial main" >> /etc/apt/sources.list.d/firefox.list \
 	&& apt-get update && apt-get install -y \
-        apulse \
+	apulse \
 	ca-certificates \
 	firefox \
 	hicolor-icon-theme \
 	libasound2 \
 	libgl1-mesa-dri \
 	libgl1-mesa-glx \
-        libpulse0 \
+	libpulse0 \
 	--no-install-recommends \
 	&& rm -rf /var/lib/apt/lists/*
 
@@ -25,8 +25,6 @@ COPY local.conf /etc/fonts/local.conf
 
 RUN echo 'pref("browser.tabs.remote.autostart", false);' >> /etc/firefox/syspref.js
 
-RUN echo "#! /bin/bash \n\
-[ -e /dev/snd ] && exec apulse firefox || exec firefox \n\
-" >/usr/local/bin/startfirefox && chmod +x /usr/local/bin/startfirefox
+COPY entrypoint.sh /usr/bin/startfirefox
 
-ENTRYPOINT [ "/usr/local/bin/startfirefox" ]
+ENTRYPOINT [ "startfirefox" ]
diff --git a/firefox/entrypoint.sh b/firefox/entrypoint.sh
new file mode 100755
index 0000000..7f8e107
--- /dev/null
+++ b/firefox/entrypoint.sh
@@ -0,0 +1,3 @@
+#!/bin/bash
+
+[ -e /dev/snd ] && exec apulse firefox || exec firefox