diff --git a/.travis.yml b/.travis.yml
index aec36607..ed2221a2 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -34,8 +34,8 @@ cache:
   directories:
     - $TRAVIS_BUILD_DIR/node_modules
     - $TRAVIS_BUILD_DIR/bower_components
-    - $HOME/boost_1_62_0/boost
-    - $HOME/boost_1_62_0/stage/lib
+    - $HOME/boost_1_61_0/boost
+    - $HOME/boost_1_61_0/stage/lib
 
 install:
   # Use GCC 5.
@@ -52,7 +52,7 @@ install:
   # Install runtime dependencies using Bower
   - bower install
   - wget https://raw.githubusercontent.com/WrinklyNinja/ci-scripts/1.0.0/install_boost.py
-  - python install_boost.py --directory ~ --boost-version 1.62.0 atomic chrono date_time filesystem iostreams locale log regex system thread
+  - python install_boost.py --directory ~ --boost-version 1.61.0 atomic chrono date_time filesystem iostreams locale log regex system thread
   # Install packages for generating documentation
   - pip install --user sphinx breathe sphinx_rtd_theme
   # Add sphinx-build to PATH
@@ -70,7 +70,7 @@ before_script:
   # Move into the cloned LOOT repo build path.
   - cd build
   # Link dynamically to the C++ standard library runtime.
-  - cmake .. -DBOOST_ROOT=~/boost_1_62_0
+  - cmake .. -DBOOST_ROOT=~/boost_1_61_0
 
 script:
   - if [ "${TRAVIS_PULL_REQUEST}" = "false" ]; then npm test; fi
diff --git a/appveyor.yml b/appveyor.yml
index a83c26e4..ae70f93e 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -7,8 +7,8 @@ configuration: Release
 cache:
   - node_modules
   - bower_components
-  - C:\projects\boost_1_62_0\boost
-  - C:\projects\boost_1_62_0\stage\lib
+  - C:\projects\boost_1_61_0\boost
+  - C:\projects\boost_1_61_0\stage\lib
 
 environment:
   github_auth_token:
@@ -23,7 +23,7 @@ install:
   - .\node_modules\.bin\bower install
   - ps: (New-Object Net.WebClient).DownloadFile('https://raw.githubusercontent.com/WrinklyNinja/ci-scripts/1.0.0/install_boost.py', "$env:APPVEYOR_BUILD_FOLDER\install_boost.py")
   - ps: (New-Object Net.WebClient).DownloadFile('https://raw.githubusercontent.com/WrinklyNinja/ci-scripts/1.0.0/delete_old_bintray_versions.py', "$env:APPVEYOR_BUILD_FOLDER\delete_old_bintray_versions.py")
-  - python %APPVEYOR_BUILD_FOLDER%\install_boost.py --directory C:\projects --boost-version 1.62.0 atomic chrono date_time filesystem iostreams locale log regex system thread
+  - python %APPVEYOR_BUILD_FOLDER%\install_boost.py --directory C:\projects --boost-version 1.61.0 atomic chrono date_time filesystem iostreams locale log regex system thread
 
 before_build:
   - cd %APPVEYOR_BUILD_FOLDER%
@@ -31,7 +31,7 @@ before_build:
   - set PATH=C:\ProgramData\chocolatey\lib\imagemagick.tool\tools;%PATH%;C:\Program Files\Inkscape
   - node scripts\create_ico.js
   - cd build
-  - cmake .. -G "Visual Studio 14 2015" -DBOOST_ROOT="C:\projects\boost_1_62_0"
+  - cmake .. -G "Visual Studio 14 2015" -DBOOST_ROOT="C:\projects\boost_1_61_0"
 
 build:
   verbosity: minimal