diff --git a/.circleci/config.yml b/.circleci/config.yml
index c80d9ed02..520fa1084 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -76,7 +76,7 @@ jobs:
       - run: pip install flake8 fonttools
       - run: pip install git+https://github.com/mesonbuild/meson
       - run: flake8 . --count --select=E901,E999,F821,F822,F823 --show-source --statistics
-      - run: meson build -Dgraphite=enabled -Dauto_features=enabled
+      - run: meson build -Dgraphite=enabled -Dauto_features=enabled -Dexperimental_api=true
       - run: meson compile -Cbuild -j9
       - run: meson test -Cbuild --print-errorlogs
       - run: meson dist -Cbuild
@@ -95,13 +95,13 @@ jobs:
       #- run: apt update || true
       - run: DEBIAN_FRONTEND=noninteractive apt install -y clang lld git binutils meson pkg-config ragel libfreetype6-dev libglib2.0-dev libcairo2-dev libicu-dev libgraphite2-dev
       # asan+ubsan
-      - run: rm -rf build && meson build --default-library=static -Db_sanitize=address,undefined --buildtype=debugoptimized --wrap-mode=nodownload
+      - run: rm -rf build && meson build --default-library=static -Db_sanitize=address,undefined --buildtype=debugoptimized --wrap-mode=nodownload -Dexperimental_api=true
       - run: ninja -Cbuild -j8 && meson test -Cbuild --print-errorlogs | asan_symbolize | c++filt
       # tsan
-      - run: rm -rf build && meson build --default-library=static -Db_sanitize=thread --buildtype=debugoptimized --wrap-mode=nodownload
+      - run: rm -rf build && meson build --default-library=static -Db_sanitize=thread --buildtype=debugoptimized --wrap-mode=nodownload -Dexperimental_api=true
       - run: ninja -Cbuild -j8 && meson test -Cbuild --print-errorlogs | asan_symbolize | c++filt
       # msan, needs --force-fallback-for=glib,freetype2 also which doesn't work yet but runs fuzzer cases at least
-      - run: rm -rf build && meson build --default-library=static -Db_sanitize=memory --buildtype=debugoptimized --wrap-mode=nodownload -Dauto_features=disabled -Dtests=enabled
+      - run: rm -rf build && meson build --default-library=static -Db_sanitize=memory --buildtype=debugoptimized --wrap-mode=nodownload -Dauto_features=disabled -Dtests=enabled -Dexperimental_api=true
       - run: ninja -Cbuild -j8 && meson test -Cbuild --print-errorlogs | asan_symbolize | c++filt
       # test -std=c++2a and -Weverything of nightly clang builds
       - run: clang -c src/harfbuzz.cc src/hb-subset*.cc -DHB_NO_MT -Werror -std=c++2a