diff --git a/.github/workflows/ci_tests_legacy.yaml b/.github/workflows/ci_tests_legacy.yaml
index 94cb15bef51..b36b06e73f5 100644
--- a/.github/workflows/ci_tests_legacy.yaml
+++ b/.github/workflows/ci_tests_legacy.yaml
@@ -35,7 +35,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-20.04, macos-12, windows-2019]
-        gmt_version: ['6.3', '6.4']
+        gmt_version: ['6.4']
     timeout-minutes: 30
     defaults:
       run: