diff --git a/appveyor.yml b/appveyor.yml
index 081cf2b..ffd5334 100755
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -29,6 +29,9 @@
 environment:
   BOOST_ROOT: C:\Libraries\boost_1_59_0
   BOOST_LIBRARYDIR: C:\Libraries\boost_1_59_0\lib64-msvc-14.0
+  # Unfurtunately, these versions need manual update because old versions are quickly deleted.
+  ANT_VERSION: 1.9.7
+  OPENSSL_VERSION: 1_0_2h
 
 install:
 - '"C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\vcvarsall.bat" x64'
@@ -41,9 +44,8 @@
 - cmake --build . --config release
 - cd ..
   # OpenSSL
-  # Unfurtunately, OpenSSL version below needs constant update (2 places) because old versions are quickly deleted.
-- appveyor DownloadFile https://slproweb.com/download/Win64OpenSSL-1_0_2h.exe
-- ps: Start-Process Win64OpenSSL-1_0_2h.exe -ArgumentList "/silent /verysilent /sp- /suppressmsgboxes" -Wait
+- appveyor DownloadFile https://slproweb.com/download/Win64OpenSSL-%OPENSSL_VERSION%.exe
+- ps: Start-Process "Win64OpenSSL-${env:OPENSSL_VERSION}.exe" -ArgumentList "/silent /verysilent /sp- /suppressmsgboxes" -Wait
   # Libevent
 - appveyor DownloadFile https://github.com/libevent/libevent/releases/download/release-2.0.22-stable/libevent-2.0.22-stable.tar.gz
 - 7z x libevent-2.0.22-stable.tar.gz -so | 7z x -si -ttar > nul
@@ -55,15 +57,15 @@
 - move *.h include\
 - cd ..
 - cinst winflexbison
-- appveyor DownloadFile http://www.us.apache.org/dist/ant/binaries/apache-ant-1.9.7-bin.zip
-- 7z x apache-ant-1.9.7-bin.zip > nul
+- appveyor DownloadFile http://www.us.apache.org/dist/ant/binaries/apache-ant-%ANT_VERSION%-bin.zip
+- 7z x apache-ant-%ANT_VERSION%-bin.zip > nul
 - cd %APPVEYOR_BUILD_FOLDER%
 # TODO: Enable Haskell build
 # - cinst HaskellPlatform -version 2014.2.0.0
 
 
 build_script:
-- set PATH=C:\ProgramData\chocolatey\bin;C:\apache-ant-1.9.7\bin;%PATH%
+- set PATH=C:\ProgramData\chocolatey\bin;C:\apache-ant-%ANT_VERSION%\bin;%PATH%
 - set JAVA_HOME=C:\Program Files\Java\jdk1.7.0
 - set PATH=%JAVA_HOME%\bin;%PATH%
 # - set PATH=%PATH%;C:\Program Files (x86)\Haskell Platform\2014.2.0.0\bin