diff --git a/.github/workflows/ci_tests.yaml b/.github/workflows/ci_tests.yaml
index 9f40a29fb7a..0708d53b775 100644
--- a/.github/workflows/ci_tests.yaml
+++ b/.github/workflows/ci_tests.yaml
@@ -61,15 +61,15 @@ jobs:
           path: |
             ~/.gmt/cache
             ~/.gmt/server
-          key: cache-gmt-${{ github.ref }}-${{ runner.os }}-20200609
-          restore-keys: cache-gmt-refs/heads/master-
+          key: cache-gmt-${{ runner.os }}-${{ github.ref }}-20200609
+          restore-keys: cache-gmt-${{ runner.os }}-refs/heads/master-
 
       # Workaround for the timeouts of 'gmt which' on Linux and Windows
       - name: Download remote data using wget (Linux & Windows)
         shell: bash -l {0}
         run: |
           if [ "$RUNNER_OS" == "Windows" ]; then choco install wget; fi  # install wget on Windows
-          mkdir ~/.gmt ~/.gmt/cache ~/.gmt/server
+          mkdir -p ~/.gmt ~/.gmt/cache ~/.gmt/server
           wget --no-check-certificate https://oceania.generic-mapping-tools.org/gmt_hash_server.txt -P ~/.gmt/server/
           for data in earth_relief_01d.grd earth_relief_30m.grd earth_relief_10m.grd; do
             wget --no-check-certificate https://oceania.generic-mapping-tools.org/${data} -P ~/.gmt/server/