diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index 8541614..54c525c 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -84,9 +84,10 @@ jobs:
         with:
           python-version: ${{ matrix.python }}
 
+      # Using older boost version to avoid compiler errors with io_service
       - name: Install dependencies
         run: |
-          brew install eigen boost
+          brew install eigen boost@1.86
           pip install cmake ninja wheel
 
       - name: Build