diff --git a/Dockerfile b/Dockerfile
index 4d72965..b613c24 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -3,7 +3,13 @@
 FROM ubuntu:16.04
 MAINTAINER Michael Stucki <michael@stucki.io>
 
+
 ENV \
+# ccache specifics
+    CCACHE_SIZE=50G \
+    CCACHE_DIR=/srv/ccache \
+    USE_CCACHE=1 \
+    CCACHE_COMPRESS=1 \
 # Extra include PATH, it may not include /usr/local/(s)bin on some systems
     PATH=$PATH:/usr/local/bin/
 
@@ -79,10 +85,6 @@ RUN chmod a+x /home/build/startup.sh
 # Fix ownership
 RUN chown -R build:build /home/build
 
-# Set global variables
-ADD android-env-vars.sh /etc/android-env-vars.sh
-RUN echo "source /etc/android-env-vars.sh" >> /etc/bash.bashrc
-
 VOLUME /home/build/android
 VOLUME /srv/ccache
 
diff --git a/android-env-vars.sh b/android-env-vars.sh
deleted file mode 100644
index 141f7d1..0000000
--- a/android-env-vars.sh
+++ /dev/null
@@ -1,3 +0,0 @@
-export USE_CCACHE=1
-export CCACHE_DIR=/srv/ccache
-export CCACHE_COMPRESS=1
diff --git a/startup.sh b/startup.sh
index be5f50a..701a16f 100644
--- a/startup.sh
+++ b/startup.sh
@@ -1,9 +1,9 @@
 #!/bin/sh
 
 # Initialize ccache if needed
-if [ ! -f /srv/ccache/ccache.conf ]; then
+if [ ! -f ${CCACHE_DIR}/ccache.conf ]; then
 	echo "Initializing ccache in /srv/ccache..."
-	CCACHE_DIR=/srv/ccache ccache -M 50G
+	ccache -M ${CCACHE_SIZE}
 fi
 
 export USER="build"