diff --git a/.github/workflows/main-stock-ubuntu.yml b/.github/workflows/main-stock-ubuntu.yml
index 786887c0..d880bf82 100644
--- a/.github/workflows/main-stock-ubuntu.yml
+++ b/.github/workflows/main-stock-ubuntu.yml
@@ -53,6 +53,10 @@ jobs:
           sudo apt install -y doxygen
           echo "::endgroup"
 
+          echo "::group::sphinx install"
+          sudo apt install -y sphinx
+          echo "::endgroup"
+
           #echo "::group::clang18 install"
           #sudo apt install -y clang-18
           #echo "::group::lldb18 install"