diff --git a/images/ubuntu/Dockerfile b/images/ubuntu/Dockerfile
index f585919..50ae21f 100644
--- a/images/ubuntu/Dockerfile
+++ b/images/ubuntu/Dockerfile
@@ -4,10 +4,16 @@ MAINTAINER AshDev <ashdevfr@gmail.com>
 ENV DEBIAN_FRONTEND noninteractive
 
 RUN apt-get update -y; apt-get upgrade -y
-RUN apt-get install -y software-properties-common
+RUN apt-get install -y software-properties-common apt-utils
 RUN add-apt-repository ppa:webupd8team/java -y
-RUN apt-get install -y curl openjdk-8-jdk supervisor pwgen
-RUN apt-get update && apt-get install -y wget git && apt-get clean all
+RUN apt-get install -y curl \
+                       openjdk-8-jdk \
+                       supervisor \
+                       pwgen \
+                       sudo \
+                       wget \
+                       git
+RUN apt-get clean all
 
 ENV APP_NAME=server
 #default directory for SPIGOT-server
diff --git a/images/ubuntu/lib/scripts/spigot_init.sh b/images/ubuntu/lib/scripts/spigot_init.sh
index 6bc7498..b3cc986 100644
--- a/images/ubuntu/lib/scripts/spigot_init.sh
+++ b/images/ubuntu/lib/scripts/spigot_init.sh
@@ -1,6 +1,8 @@
 #!/bin/bash
 set -e
 
+echo "SPIGOT_HOME=$SPIGOT_HOME/"
+
 # Change owner to minecraft.
 if [ "$SKIPCHMOD" != "true" ]; then
   sudo chown -R minecraft:minecraft $SPIGOT_HOME/
@@ -57,11 +59,20 @@ fi
 # Select the spigot.jar for this particular rev.
 rm -f $SPIGOT_HOME/spigot.jar && ln -s $SPIGOT_HOME/spigot-$REV.jar $SPIGOT_HOME/spigot.jar
 
+# Avoid to be blacklisted by bukkit's cloudflare. Only redownload if asked.
+if [ -z "$FORECEREBUILDBUKKIT" ]; then
+    REBUILD_BUKKIT=false
+fi
+
 # Install WorldBorder.
 if [ -n "$WORLDBORDER" ]; then
   if [ "$WORLDBORDER" = "true" ]; then
-    echo "Downloading WorldBorder..."
-    wget -O $SPIGOT_HOME/plugins/WorldBorder.jar https://dev.bukkit.org/projects/worldborder/files/latest
+    if [ ! -f $SPIGOT_HOME/plugins/WorldBorder.jar ] || [ "$REBUILD_BUKKIT" = "true" ]; then
+      echo "Downloading WorldBorder..."
+      wget -O $SPIGOT_HOME/plugins/WorldBorder.jar https://dev.bukkit.org/projects/worldborder/files/latest
+    else
+      echo "Using preiviously downloaded WorldBorder..."
+    fi
   else
     echo "Removing WorldBorder..."
     rm -f $SPIGOT_HOME/plugins/WorldBorder.jar
@@ -119,8 +130,12 @@ fi
 # Install Clearlag.
 if [ -n "$CLEARLAG" ]; then
   if [ "$CLEARLAG" = "true" ]; then
-    echo "Downloading ClearLag..."
-    wget -O $SPIGOT_HOME/plugins/Clearlag.jar https://dev.bukkit.org/projects/clearlagg/files/latest
+    if [ ! -f $SPIGOT_HOME/plugins/Clearlag.jar ] || [ "$REBUILD_BUKKIT" = "true" ]; then
+      echo "Downloading ClearLag..."
+      wget -O $SPIGOT_HOME/plugins/Clearlag.jar https://dev.bukkit.org/projects/clearlagg/files/latest
+    else
+      echo "Using preiviously downloaded ClearLag..."
+    fi
   else
     echo "Removing Clearlag..."
     rm -f $SPIGOT_HOME/plugins/Clearlag.jar
@@ -130,8 +145,12 @@ fi
 # Install PermissionsEx.
 if [ -n "$PERMISSIONSEX" ]; then
   if [ "$PERMISSIONSEX" = "true" ]; then
-    echo "Downloading PermissionsEx..."
-    wget -O $SPIGOT_HOME/plugins/PermissionsEx.jar https://dev.bukkit.org/projects/permissionsex/files/latest
+    if [ ! -f $SPIGOT_HOME/plugins/PermissionsEx.jar ] || [ "$REBUILD_BUKKIT" = "true" ]; then 
+      echo "Downloading PermissionsEx..."
+      wget -O $SPIGOT_HOME/plugins/PermissionsEx.jar https://dev.bukkit.org/projects/permissionsex/files/latest
+    else
+      echo "Using preiviously downloaded PremissionsEx..."
+    fi
   else
     echo "Removing PermissionsEx..."
     rm -f $SPIGOT_HOME/plugins/PermissionsEx.jar