diff --git a/unit-files/backup-u@.service b/unit-files/backup-u@.service
index 15ae63bc23dd72e42f50ef669fa387521b0cefed..cf441e0f2d54866af024e877428e614886d72e5b 100644
--- a/unit-files/backup-u@.service
+++ b/unit-files/backup-u@.service
@@ -20,7 +20,7 @@ ExecStart=/bin/bash -euxc ' \
     --rm \
     --name backup-%i \
     -h backup.container \
-    --cpu-shares=100 \
+    --cpu-shares=40 \
     -v /root:/root \
     -v /data/domains/%i:/backup indiepaas/duplicity \
       --full-if-older-than 1W \
diff --git a/unit-files/backup@.service b/unit-files/backup@.service
index 678fbce6077d31f8a23c9f8f070f1c994a7481d5..29da1344f6db4779cada215fe1b0856458bb2422 100644
--- a/unit-files/backup@.service
+++ b/unit-files/backup@.service
@@ -37,7 +37,7 @@ ExecStart=/bin/bash -euxc ' \
   /bin/docker run \
     --rm \
     --name backup-%i \
-    --cpu-shares=100 \
+    --cpu-shares=40 \
     -h backup.container \
     -v /root:/root \
     -v /data/domains/%i:/backup indiepaas/duplicity \