diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index bd1bb555..0fa84ce0 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -837,10 +837,20 @@ jobs:
           ./autogen.sh && ./configure --prefix=${{ env.CI_INSTALL }} && make clean && make install && ls -RlAh ${{ env.CI_INSTALL }}
           gcc -o ecdsa examples/ecdsa.c $(PKG_CONFIG_PATH=${{ env.CI_INSTALL }}/lib/pkgconfig pkg-config --cflags --libs libsecp256k1) -Wl,-rpath,"${{ env.CI_INSTALL }}/lib" && ./ecdsa
 
+      # The experimental module flags are the only CMake coverage this fork's
+      # modules get. Every other CMake invocation in this workflow is the
+      # win64-native job, which builds with MSVC and /WX and has never
+      # compiled any of them; turning them on there would be a first port,
+      # not a regression guard. This step is gcc on Linux, so it exercises
+      # what actually needs guarding: the SECP256K1_EXPERIMENTAL gate, the
+      # dependent-module block ordering in src/CMakeLists.txt (where a block
+      # placed after the one it force-enables silently produces a library
+      # whose secp256k1.c never included the module), and the PUBLIC_HEADER
+      # appends, which the install step then checks landed.
       - name: Check installation with CMake
         env:
           CI_BUILD: ${{ runner.temp }}/${{ github.run_id }}${{ github.action }}/build
           CI_INSTALL: ${{ runner.temp }}/${{ github.run_id }}${{ github.action }}/install
         run: |
-          cmake -B ${{ env.CI_BUILD }} -DCMAKE_INSTALL_PREFIX=${{ env.CI_INSTALL }} && cmake --build ${{ env.CI_BUILD }} && cmake --install ${{ env.CI_BUILD }} && ls -RlAh ${{ env.CI_INSTALL }}
+          cmake -B ${{ env.CI_BUILD }} -DCMAKE_INSTALL_PREFIX=${{ env.CI_INSTALL }} -DSECP256K1_EXPERIMENTAL=ON -DSECP256K1_ENABLE_MODULE_FROST=ON -DSECP256K1_ENABLE_MODULE_CHILLDKG=ON -DSECP256K1_ENABLE_MODULE_ICEBERG=ON -DSECP256K1_ENABLE_MODULE_PREFRACTAL=ON -DSECP256K1_ENABLE_MODULE_FROST_ENROLLMENT=ON && cmake --build ${{ env.CI_BUILD }} && cmake --install ${{ env.CI_BUILD }} && ls -RlAh ${{ env.CI_INSTALL }}
           gcc -o ecdsa examples/ecdsa.c -I ${{ env.CI_INSTALL }}/include -L ${{ env.CI_INSTALL }}/lib*/ -l secp256k1 -Wl,-rpath,"${{ env.CI_INSTALL }}/lib",-rpath,"${{ env.CI_INSTALL }}/lib64" && ./ecdsa