diff --git a/src/restic_compose_backup/containers_db.py b/src/restic_compose_backup/containers_db.py
index ddb1a22..f5e6b82 100644
--- a/src/restic_compose_backup/containers_db.py
+++ b/src/restic_compose_backup/containers_db.py
@@ -47,7 +47,7 @@ class MariadbContainer(Container):
             "--port",
             creds['port'],
             "--outputdir",
-            destination,
+            f"{destination}",
             "--no-views",
             "--compress",
             "--regex '^(?!(mysql\.))'"
@@ -115,7 +115,7 @@ class MysqlContainer(Container):
             "--port",
             creds['port'],
             "--outputdir",
-            destination,
+            f"{destination}",
             "--no-views",
             "--compress",
             "--regex '^(?!(mysql\.))'"