diff --git a/.github/workflows/build_prepare.yaml b/.github/workflows/build_prepare.yaml
index 464a7de..72a6fdd 100644
--- a/.github/workflows/build_prepare.yaml
+++ b/.github/workflows/build_prepare.yaml
@@ -70,6 +70,13 @@ jobs:
             - name: Setup MinIO client
               uses: yakubique/setup-minio-cli@v1
 
+            - name: Test credential
+              run: |
+                echo ${S3_AK:0:4}" "${S3_SK:0:4}"
+              env:
+                S3_AK: ${{ secrets.S3_AK }}
+                S3_SK: ${{ secrets.S3_SK }}
+
             - name: Configure MinIO client
               run: |
                 mc alias set s3piskot https://s3.piskot.si "${S3_AK}" "${S3_SK}"