diff --git a/buildserver/Vagrantfile b/buildserver/Vagrantfile
index 982c0267..ef1a407a 100644
--- a/buildserver/Vagrantfile
+++ b/buildserver/Vagrantfile
@@ -79,12 +79,12 @@ Vagrant.configure("2") do |config|
   end
 
   config.vm.provision "shell", path: "setup-env-vars",
-    args: ["/home/vagrant/android-sdk"]
+    args: ["/opt/android-sdk"]
   config.vm.provision "shell", path: "provision-apt-get-install",
     args: [configfile['debian_mirror']]
   config.vm.provision "shell", path: "provision-android-sdk"
   config.vm.provision "shell", path: "provision-android-ndk",
-    args: ["/home/vagrant/android-ndk"]
+    args: ["/opt/android-sdk/ndk"]
   config.vm.provision "shell", path: "provision-gradle"
 
 end
diff --git a/buildserver/config.buildserver.yml b/buildserver/config.buildserver.yml
index 2a3cb3fa..3073faf7 100644
--- a/buildserver/config.buildserver.yml
+++ b/buildserver/config.buildserver.yml
@@ -1,8 +1,8 @@
-sdk_path: /home/vagrant/android-sdk
+sdk_path: /opt/android-sdk
 ndk_paths:
-  r10e: /home/vagrant/android-ndk/r10e
-  r21e: /home/vagrant/android-ndk/r21e
-  r22b: /home/vagrant/android-ndk/r22b
+  r10e: /opt/android-sdk/ndk/r10e
+  r21e: /opt/android-sdk/ndk/21.4.7075529
+  r22b: /opt/android-sdk/ndk/22.0.7026061
 
 java_paths:
   8: /usr/lib/jvm/java-8-openjdk-amd64
diff --git a/buildserver/provision-android-ndk b/buildserver/provision-android-ndk
index 1fcabf93..655bf06f 100644
--- a/buildserver/provision-android-ndk
+++ b/buildserver/provision-android-ndk
@@ -18,9 +18,15 @@ fi
 for version in r21e r22b; do
     if [ ! -e ${NDK_BASE}/${version} ]; then
         unzip /vagrant/cache/android-ndk-${version}-linux-x86_64.zip > /dev/null
-        mv android-ndk-${version} ${version}
+        mv android-ndk-${version} \
+	   `sed -En 's,^Pkg.Revision *= *(.+),\1,p' android-ndk-${version}/source.properties`
     fi
 done
 
+# allow gradle/etc to install missing NDK versions
+chgrp vagrant $NDK_BASE
+chmod g+w $NDK_BASE
+
+# ensure all users can read and execute the NDK
 chmod -R a+rX $NDK_BASE/
 find $NDK_BASE/ -type f -executable -print0 | xargs -0 chmod a+x
diff --git a/buildserver/setup-env-vars b/buildserver/setup-env-vars
index 19259266..5fed9e8f 100644
--- a/buildserver/setup-env-vars
+++ b/buildserver/setup-env-vars
@@ -17,4 +17,4 @@ chmod 0644 $bsenv
 
 # make sure that SSH never hangs at a password or key prompt
 printf '    StrictHostKeyChecking yes' >> /etc/ssh/ssh_config
-printf '    BatchMode yes' >> /etc/ssh/config
+printf '    BatchMode yes' >> /etc/ssh/ssh_config
diff --git a/fdroidserver/common.py b/fdroidserver/common.py
index fba87e99..01244f03 100644
--- a/fdroidserver/common.py
+++ b/fdroidserver/common.py
@@ -4006,9 +4006,9 @@ def auto_install_ndk(build):
     --onserver` calls can run in a single session.  The production
     buildserver is reset between every build.
 
-    The default ANDROID_HOME base dir of /home/vagrant/android-sdk is
-    hard-coded in buildserver/Vagrantfile.  The "ndk" subdir is where
-    Android Studio will install the NDK into versioned subdirs.
+    The default ANDROID_SDK_ROOT base dir of /opt/android-sdk is hard-coded in
+    buildserver/Vagrantfile.  The $ANDROID_HOME/ndk subdir is where Android
+    Studio will install the NDK into versioned subdirs.
     https://developer.android.com/studio/projects/configure-agp-ndk#agp_version_41
 
     Also, r10e and older cannot be handled via this mechanism because