diff --git a/.circleci/config.yml b/.circleci/config.yml
index 24e81e2..9d0b79b 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -2,7 +2,7 @@ version: 2
 jobs:
   build:
     machine:
-      image: ubuntu-1604:202004-01
+      image: ubuntu-2004:202111-02
 
     java:
       version: oraclejdk8
diff --git a/build.gradle b/build.gradle
index 5c3bd7f..d8def15 100644
--- a/build.gradle
+++ b/build.gradle
@@ -41,7 +41,7 @@ make_data_catalog.outputs.files.each { xml ->
     dependsOn "make_data_catalog"
     input xml
     output "${buildDir}/validated/${fn}"
-    schema "src/data/xmlcatalogs.org/schema/1.1/catalog.rng"
+    schema "${projectDir}/src/data/xmlcatalogs.org/schema/1.1/catalog.rng"
   }
   validate.dependsOn(t)
 }