diff --git a/Dockerfile b/Dockerfile
index 2f5f88a..d82ca22 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,9 +1,9 @@
 FROM alpine:3.4
 MAINTAINER Adam Dodman <adam.dodman@gmx.com>
 
-ENV UID=787 UNAME=plex GID=990 GNAME=media
-ENV debs "libc6 libgcc1 libstdc++6 plexmediaserver"
-ENV destdir "/plex"
+ENV UID=787 UNAME=plex GID=990 GNAME=media DESTDIR="/plex"
+ENV GLIBC_LIBRARY_PATH="$DESTDIR/lib" GLIBC_LD_LINUX_SO="/plex/lib/ld-linux-x86-64.so.2"
+ENV DEBS="libc6 libgcc1 libstdc++6 plexmediaserver"
 
 ADD start_pms.patch /tmp/start_pms.patch
 
@@ -20,7 +20,7 @@ RUN addgroup -g $GID $GNAME \
  && wget http://ftp.debian.org/debian/pool/main/g/gcc-4.9/libstdc++6_4.9.2-10_amd64.deb \
  && wget -O plexmediaserver.deb 'https://plex.tv/downloads/latest/1?channel=8&build=linux-ubuntu-x86_64&distro=ubuntu' \
 
- && for pkg in $debs; do \
+ && for pkg in $DEBS; do \
         mkdir $pkg; \
         cd $pkg; \
         ar x ../$pkg*.deb; \
@@ -28,17 +28,11 @@ RUN addgroup -g $GID $GNAME \
         cd ..; \
     done \
 
- && mkdir -p $destdir/lib \
+ && mkdir -p $GLIBC_LIBRARY_PATH \
 
- && mv libc6/lib/x86_64-linux-gnu/* $destdir/lib \
- && mv libgcc1/lib/x86_64-linux-gnu/* $destdir/lib \
- && mv libstdc++6/usr/lib/x86_64-linux-gnu/* $destdir/lib \
-
- && echo "export GLIBC_LIBRARY_PATH=/plex/lib" >"$destdir/lib/vars.sh" \
- && echo "export GLIBC_LD_LINUX_SO=/plex/lib/ld-linux-x86-64.so.2" >>"$destdir/lib/vars.sh" \
- && chmod +x $destdir/lib/vars.sh \
-
- && . $destdir/lib/vars.sh \
+ && mv libc6/lib/x86_64-linux-gnu/* $GLIBC_LIBRARY_PATH \
+ && mv libgcc1/lib/x86_64-linux-gnu/* $GLIBC_LIBRARY_PATH \
+ && mv libstdc++6/usr/lib/x86_64-linux-gnu/* $GLIBC_LIBRARY_PATH \
 
  && find plexmediaserver/usr/lib/plexmediaserver -type f -perm /0111 -exec sh -c "file --brief \"{}\" | grep -q "ELF" && patchelf --set-interpreter \"$GLIBC_LD_LINUX_SO\" \"{}\" " \; \
 
@@ -46,10 +40,10 @@ RUN addgroup -g $GID $GNAME \
  && cd plexmediaserver/usr/sbin/ \
  && patch < start_pms.patch \
  && cd /tmp \
- && sed -i "s|<destdir>|$destdir|" plexmediaserver/usr/sbin/start_pms \
+ && sed -i "s|<destdir>|$DESTDIR|" plexmediaserver/usr/sbin/start_pms \
 
- && mv plexmediaserver/usr/sbin/start_pms $destdir/ \
- && mv plexmediaserver/usr/lib/plexmediaserver $destdir/plex-media-server \
+ && mv plexmediaserver/usr/sbin/start_pms $DESTDIR/ \
+ && mv plexmediaserver/usr/lib/plexmediaserver $DESTDIR/plex-media-server \
 
  && apk del --no-cache xz binutils patchelf file \
  && rm -rf /tmp/*