diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index aa2f0e4..dd6cbf5 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -27,6 +27,7 @@ jobs:
           openssl version -a
       - name: Build Extension
         run: |
+          ls /usr/include/postgresql/
           cc -fPIC -c pgcrypsi.c -I /usr/include/postgresql/10/server/
           cc -shared -o pgcrypsi.so pgcrypsi.o
       - name: Check libdir