diff --git a/bootstrap.sh b/bootstrap.sh
index d5a24af6550..3c9e1f5be31 100755
--- a/bootstrap.sh
+++ b/bootstrap.sh
@@ -179,15 +179,14 @@ function install_zookeeper() {
   zk="zookeeper-$version"
   wget "http://apache.org/dist/zookeeper/$zk/$zk.tar.gz"
   tar -xzf "$zk.tar.gz"
+  ant -f "$zk/build.xml" package
+  ant -f "$zk/src/contrib/fatjar/build.xml" jar
   mkdir -p lib
-  cp "$zk/contrib/fatjar/$zk-fatjar.jar" lib
-  # TODO(sougou): when version changes, see if we can drop the 'zip -d' hack to get the fatjars working.
-  #               If yes, also delete "zip" from the Dockerfile files and the manual build instructions again.
-  # 3.4.13 workaround: Delete META-INF files which should not be in there.
-  zip -d "lib/$zk-fatjar.jar" 'META-INF/*.SF' 'META-INF/*.RSA' 'META-INF/*SF'
+  cp "$zk/build/contrib/fatjar/zookeeper-dev-fatjar.jar" "lib/$zk-fatjar.jar"
+  zip -d "lib/$zk-fatjar.jar" 'META-INF/*.SF' 'META-INF/*.RSA' 'META-INF/*SF' || true # needed for >=3.4.10 <3.5
   rm -rf "$zk" "$zk.tar.gz"
 }
-zk_ver=3.4.13
+zk_ver=${ZK_VERSION:-3.4.13}
 install_dep "Zookeeper" "$zk_ver" "$VTROOT/dist/vt-zookeeper-$zk_ver" install_zookeeper
 
 
diff --git a/docker/bootstrap/Dockerfile.common b/docker/bootstrap/Dockerfile.common
index 6d96504e03c..c1236160481 100644
--- a/docker/bootstrap/Dockerfile.common
+++ b/docker/bootstrap/Dockerfile.common
@@ -27,6 +27,7 @@ RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y --no-ins
     xvfb \
     zip \
     libz-dev \
+    ant \
     && rm -rf /var/lib/apt/lists/*
 
 # Install Maven 3.1+
diff --git a/go/vt/zkctl/zksrv.sh b/go/vt/zkctl/zksrv.sh
index 30f4f2e1ef4..b306637836e 100755
--- a/go/vt/zkctl/zksrv.sh
+++ b/go/vt/zkctl/zksrv.sh
@@ -21,7 +21,7 @@ logdir="$1"
 config="$2"
 pidfile="$3"
 
-zk_ver=3.4.13
+zk_ver=${ZK_VERSION:-3.4.13}
 classpath="$VTROOT/dist/vt-zookeeper-$zk_ver/lib/zookeeper-$zk_ver-fatjar.jar:/usr/local/lib/zookeeper-$zk_ver-fatjar.jar:/usr/share/java/zookeeper-$zk_ver.jar"
 
 mkdir -p "$logdir"