diff --git a/.github/workflows/ubuntu.yml b/.github/workflows/ubuntu.yml
index c744e7e..d59b59b 100644
--- a/.github/workflows/ubuntu.yml
+++ b/.github/workflows/ubuntu.yml
@@ -23,6 +23,7 @@ jobs:
       run: |
         git clone https://github.com/ruby/ruby.git --depth 1
         cd ruby
+        ./autogen.sh
         ./configure cppflags=-DUNIVERSAL_PARSER
         make
         sudo make install