thodg/libgit2

diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index 620601d..db64c7d 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -16,6 +16,7 @@ jobs:
       imageName: 'libgit2/trusty-openssl:latest'
       environmentVariables: |
        CC=gcc
+       CMAKE_OPTIONS=-DUSE_HTTPS=OpenSSL
        LEAK_CHECK=valgrind
 
 - job: linux_trusty_gcc_mbedtls
@@ -41,6 +42,7 @@ jobs:
       imageName: 'libgit2/trusty-openssl:latest'
       environmentVariables: |
        CC=clang
+       CMAKE_OPTIONS=-DUSE_HTTPS=OpenSSL
        LEAK_CHECK=valgrind
 
 - job: linux_trusty_clang_mbedtls
@@ -69,6 +71,7 @@ jobs:
         TMPDIR: $(Agent.TempDirectory)
         PKG_CONFIG_PATH: /usr/local/opt/openssl/lib/pkgconfig
         LEAK_CHECK: leaks
+        CMAKE_OPTIONS: -G Ninja
 
 - job: windows_vs_amd64
   displayName: 'Windows (Visual Studio; amd64)'
diff --git a/ci/setup-osx.sh b/ci/setup-osx.sh
index 564910e..2e630ee 100755
--- a/ci/setup-osx.sh
+++ b/ci/setup-osx.sh
@@ -3,6 +3,6 @@
 set -x
 
 brew update
-brew install pkgconfig zlib curl openssl libssh2
+brew install pkgconfig zlib curl openssl libssh2 ninja
 
 ln -s /Applications/Xcode.app/Contents/Developer/usr/lib/libLeaksAtExit.dylib /usr/local/lib