diff --git a/.travis.yml b/.travis.yml
index 10c93ddc..35bfc279 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -30,10 +30,10 @@ install:
   - export PATH="$HOME/.local/bin:$PATH"
   # Don't install Doxygen from the repositories, it also gets the LaTeX packages
   # so is a ~ 700 MB download.
-  - wget http://doxygen.nl/files/doxygen-1.8.14.linux.bin.tar.gz
-  - tar -xf doxygen-1.8.14.linux.bin.tar.gz
+  - wget http://doxygen.nl/files/doxygen-1.8.15.linux.bin.tar.gz
+  - tar -xf doxygen-1.8.15.linux.bin.tar.gz
   # Add Doxygen binary path to PATH
-  - export PATH="$PWD/doxygen-1.8.14/bin:$PATH"
+  - export PATH="$PWD/doxygen-1.8.15/bin:$PATH"
   # Install cbindgen for generating C++ headers for Rust dependencies.
   - cbindgen --version || cargo install cbindgen --version 0.6.6
 
diff --git a/appveyor.yml b/appveyor.yml
index b0986c12..88444218 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -27,7 +27,7 @@ install:
   - rustup target add i686-pc-windows-msvc
   - where cbindgen || cargo install cbindgen --version 0.6.6
   # Download and extract Doxygen manually because Chocolatey is flaky.
-  - curl -sSf -o doxygen.zip http://doxygen.nl/files/doxygen-1.8.14.windows.x64.bin.zip
+  - curl -sSf -o doxygen.zip http://doxygen.nl/files/doxygen-1.8.15.windows.x64.bin.zip
   - ps: Expand-Archive doxygen.zip -DestinationPath "$env:APPVEYOR_BUILD_FOLDER\doxygen"
   - python -m pip install -r docs/requirements.txt
   - ps: (New-Object Net.WebClient).DownloadFile('https://raw.githubusercontent.com/Ortham/ci-scripts/2.0.0/delete_old_bintray_versions.py', "$env:APPVEYOR_BUILD_FOLDER\delete_old_bintray_versions.py")