diff --git a/.github/workflows/test-postgis.yml b/.github/workflows/test-postgis.yml
index 73d0148b..ea12103c 100644
--- a/.github/workflows/test-postgis.yml
+++ b/.github/workflows/test-postgis.yml
@@ -27,6 +27,11 @@ jobs:
         redmine_version: ${{ fromJSON(vars.PLUGIN_TEST_MATRIX_REDMINE_VERSION) }}
         ruby_version: ${{ fromJSON(vars.PLUGIN_TEST_MATRIX_RUBY_VERSION) }}
         db_version: [12-3.0, 15-3.3]
+        exclude:
+          - redmine: 5.1-stable
+            ruby_version: '3.0'
+          - redmine: master
+            ruby_version: '3.0'
 
     services:
       postgres: