diff --git a/.readthedocs.yaml b/.readthedocs.yaml
index 8d888364c3..355531d453 100644
--- a/.readthedocs.yaml
+++ b/.readthedocs.yaml
@@ -4,12 +4,23 @@
 
 version: 2
 
+submodules:
+  include:
+    - docs/riscv-isa/riscv-isa-manual
+
 build:
   os: "ubuntu-20.04"
   tools:
     python: "3.9"
     nodejs: "20"
     ruby: "3.3"
+  apt_packages:
+    - cmake
+    - bison
+    - flex
+    - libpango1.0-dev
+    - libgdk-pixbuf2.0-0
+    - libgtk2.0-dev
   jobs:
     post_install:
       - npm install docs/riscv-isa/riscv-isa-manual/dependencies