diff --git a/packages/apps/mongodb/templates/_backup.tpl b/packages/apps/mongodb/templates/_backup.tpl
new file mode 100644
index 000000000..516cb4b44
--- /dev/null
+++ b/packages/apps/mongodb/templates/_backup.tpl
@@ -0,0 +1,13 @@
+{{- /*
+  Bucket and prefix of backup.destinationPath. The bootstrap restore has to
+  read from the place the backup storage writes to. The operator builds the
+  restore's storage from backupSource.s3 alone and takes only the backup name
+  from backupSource.destination, so both templates derive the pair here.
+*/}}
+{{- define "mongodb.backup.bucket" -}}
+{{- .Values.backup.destinationPath | trimPrefix "s3://" | regexFind "^[^/]+" -}}
+{{- end -}}
+
+{{- define "mongodb.backup.prefix" -}}
+{{- .Values.backup.destinationPath | trimPrefix "s3://" | splitList "/" | rest | join "/" -}}
+{{- end -}}
diff --git a/packages/apps/mongodb/templates/mongodb.yaml b/packages/apps/mongodb/templates/mongodb.yaml
index 439bb978a..c12dbca07 100644
--- a/packages/apps/mongodb/templates/mongodb.yaml
+++ b/packages/apps/mongodb/templates/mongodb.yaml
@@ -244,8 +244,10 @@ spec:
       s3-storage:
         type: s3
         s3:
-          bucket: {{ .Values.backup.destinationPath | trimPrefix "s3://" | regexFind "^[^/]+" }}
-          prefix: {{ .Values.backup.destinationPath | trimPrefix "s3://" | splitList "/" | rest | join "/" }}
+          bucket: {{ include "mongodb.backup.bucket" . | quote }}
+          {{- with include "mongodb.backup.prefix" . }}
+          prefix: {{ . | quote }}
+          {{- end }}
           endpointUrl: {{ .Values.backup.endpointURL }}
           credentialsSecret: {{ .Release.Name }}-s3-creds
           insecureSkipTLSVerify: {{ .Values.backup.insecureSkipTLSVerify | default false }}
diff --git a/packages/apps/mongodb/templates/restore.yaml b/packages/apps/mongodb/templates/restore.yaml
index 083a72091..2742cc81f 100644
--- a/packages/apps/mongodb/templates/restore.yaml
+++ b/packages/apps/mongodb/templates/restore.yaml
@@ -8,6 +8,9 @@
 {{- if not .Values.backup.destinationPath }}
 {{- fail "backup.destinationPath is required when bootstrap.enabled is true" }}
 {{- end }}
+{{- if not (include "mongodb.backup.bucket" .) }}
+{{- fail "backup.destinationPath must name a bucket (s3://bucket/path/) when bootstrap.enabled is true" }}
+{{- end }}
 {{- if not .Values.backup.endpointURL }}
 {{- fail "backup.endpointURL is required when bootstrap.enabled is true" }}
 {{- end }}
@@ -33,6 +36,8 @@ spec:
     type: logical
     destination: {{ .Values.backup.destinationPath | trimSuffix "/" }}/{{ .Values.bootstrap.backupName }}
     s3:
+      bucket: {{ include "mongodb.backup.bucket" . | quote }}
+      prefix: {{ include "mongodb.backup.prefix" . | quote }}
       credentialsSecret: {{ .Release.Name }}-s3-creds
       endpointUrl: {{ .Values.backup.endpointURL }}
       insecureSkipTLSVerify: {{ .Values.backup.insecureSkipTLSVerify | default false }}
diff --git a/packages/apps/mongodb/tests/restore-storage_test.yaml b/packages/apps/mongodb/tests/restore-storage_test.yaml
new file mode 100644
index 000000000..1f1245bf8
--- /dev/null
+++ b/packages/apps/mongodb/tests/restore-storage_test.yaml
@@ -0,0 +1,133 @@
+suite: bootstrap restore reads where the backup storage writes
+
+templates:
+  - templates/mongodb.yaml
+  - templates/restore.yaml
+
+release:
+  name: test-mongodb
+  namespace: tenant-test
+
+tests:
+  - it: gives the restore the same S3 location and access as the backup storage
+    set:
+      _cluster:
+        cluster-domain: cozy.local
+      bootstrap:
+        enabled: true
+        backupName: "2026-10-01T02:00:21Z"
+      backup:
+        enabled: true
+        destinationPath: "s3://mybucket/mongodb/prod/"
+        endpointURL: "https://s3.example.org"
+        insecureSkipTLSVerify: true
+        s3AccessKey: "access"
+        s3SecretKey: "secret"
+    asserts:
+      - equal:
+          path: spec.backup.storages.s3-storage.s3.bucket
+          value: mybucket
+        template: templates/mongodb.yaml
+        documentSelector:
+          path: kind
+          value: PerconaServerMongoDB
+      - equal:
+          path: spec.backupSource.s3.bucket
+          value: mybucket
+        template: templates/restore.yaml
+      - equal:
+          path: spec.backup.storages.s3-storage.s3.prefix
+          value: mongodb/prod/
+        template: templates/mongodb.yaml
+        documentSelector:
+          path: kind
+          value: PerconaServerMongoDB
+      - equal:
+          path: spec.backupSource.s3.prefix
+          value: mongodb/prod/
+        template: templates/restore.yaml
+      - equal:
+          path: spec.backup.storages.s3-storage.s3.endpointUrl
+          value: https://s3.example.org
+        template: templates/mongodb.yaml
+        documentSelector:
+          path: kind
+          value: PerconaServerMongoDB
+      - equal:
+          path: spec.backupSource.s3.endpointUrl
+          value: https://s3.example.org
+        template: templates/restore.yaml
+      - equal:
+          path: spec.backup.storages.s3-storage.s3.credentialsSecret
+          value: test-mongodb-s3-creds
+        template: templates/mongodb.yaml
+        documentSelector:
+          path: kind
+          value: PerconaServerMongoDB
+      - equal:
+          path: spec.backupSource.s3.credentialsSecret
+          value: test-mongodb-s3-creds
+        template: templates/restore.yaml
+      - equal:
+          path: spec.backup.storages.s3-storage.s3.insecureSkipTLSVerify
+          value: true
+        template: templates/mongodb.yaml
+        documentSelector:
+          path: kind
+          value: PerconaServerMongoDB
+      - equal:
+          path: spec.backupSource.s3.insecureSkipTLSVerify
+          value: true
+        template: templates/restore.yaml
+      - equal:
+          path: spec.backup.storages.s3-storage.s3.forcePathStyle
+          value: true
+        template: templates/mongodb.yaml
+        documentSelector:
+          path: kind
+          value: PerconaServerMongoDB
+      - equal:
+          path: spec.backupSource.s3.forcePathStyle
+          value: true
+        template: templates/restore.yaml
+      - equal:
+          path: spec.backupSource.destination
+          value: s3://mybucket/mongodb/prod/2026-10-01T02:00:21Z
+        template: templates/restore.yaml
+
+  - it: keeps a numeric bucket and prefix as strings on both sides
+    set:
+      _cluster:
+        cluster-domain: cozy.local
+      bootstrap:
+        enabled: true
+        backupName: "2026-10-01T02:00:21Z"
+      backup:
+        enabled: true
+        destinationPath: "s3://2024/10"
+        endpointURL: "https://s3.example.org"
+        s3AccessKey: "access"
+        s3SecretKey: "secret"
+    asserts:
+      - equal:
+          path: spec.backup.storages.s3-storage.s3.bucket
+          value: "2024"
+        template: templates/mongodb.yaml
+        documentSelector:
+          path: kind
+          value: PerconaServerMongoDB
+      - equal:
+          path: spec.backup.storages.s3-storage.s3.prefix
+          value: "10"
+        template: templates/mongodb.yaml
+        documentSelector:
+          path: kind
+          value: PerconaServerMongoDB
+      - equal:
+          path: spec.backupSource.s3.bucket
+          value: "2024"
+        template: templates/restore.yaml
+      - equal:
+          path: spec.backupSource.s3.prefix
+          value: "10"
+        template: templates/restore.yaml
diff --git a/packages/apps/mongodb/tests/restore_test.yaml b/packages/apps/mongodb/tests/restore_test.yaml
index 8088014e0..8337873b5 100644
--- a/packages/apps/mongodb/tests/restore_test.yaml
+++ b/packages/apps/mongodb/tests/restore_test.yaml
@@ -281,6 +281,123 @@ tests:
           path: spec.backupSource.s3.forcePathStyle
           value: true
 
+  - it: sets bucket and prefix from destinationPath
+    release:
+      name: test-mongodb
+      namespace: tenant-test
+    set:
+      bootstrap:
+        enabled: true
+        backupName: "backup"
+      backup:
+        destinationPath: "s3://mybucket/mongodb/prod/"
+        endpointURL: "http://minio:9000"
+        s3AccessKey: "access"
+        s3SecretKey: "secret"
+    asserts:
+      - equal:
+          path: spec.backupSource.s3.bucket
+          value: mybucket
+      - equal:
+          path: spec.backupSource.s3.prefix
+          value: mongodb/prod/
+
+  - it: keeps a prefix without a trailing slash as given
+    release:
+      name: test-mongodb
+      namespace: tenant-test
+    set:
+      bootstrap:
+        enabled: true
+        backupName: "backup"
+      backup:
+        destinationPath: "s3://mybucket/mongodb/prod"
+        endpointURL: "http://minio:9000"
+        s3AccessKey: "access"
+        s3SecretKey: "secret"
+    asserts:
+      - equal:
+          path: spec.backupSource.s3.prefix
+          value: mongodb/prod
+      - equal:
+          path: spec.backupSource.destination
+          value: s3://mybucket/mongodb/prod/backup
+
+  - it: sets an empty prefix when destinationPath is the bucket root
+    release:
+      name: test-mongodb
+      namespace: tenant-test
+    set:
+      bootstrap:
+        enabled: true
+        backupName: "backup"
+      backup:
+        destinationPath: "s3://mybucket"
+        endpointURL: "http://minio:9000"
+        s3AccessKey: "access"
+        s3SecretKey: "secret"
+    asserts:
+      - equal:
+          path: spec.backupSource.s3.bucket
+          value: mybucket
+      - equal:
+          path: spec.backupSource.s3.prefix
+          value: ""
+      - equal:
+          path: spec.backupSource.destination
+          value: s3://mybucket/backup
+
+  - it: keeps a numeric bucket and prefix as strings
+    release:
+      name: test-mongodb
+      namespace: tenant-test
+    set:
+      bootstrap:
+        enabled: true
+        backupName: "backup"
+      backup:
+        destinationPath: "s3://2024/10"
+        endpointURL: "http://minio:9000"
+        s3AccessKey: "access"
+        s3SecretKey: "secret"
+    asserts:
+      - equal:
+          path: spec.backupSource.s3.bucket
+          value: "2024"
+      - equal:
+          path: spec.backupSource.s3.prefix
+          value: "10"
+
+  - it: fails when destinationPath names no bucket
+    release:
+      name: test-mongodb
+      namespace: tenant-test
+    set:
+      bootstrap:
+        enabled: true
+        backupName: "backup"
+      backup:
+        destinationPath: "s3://"
+        endpointURL: "http://minio:9000"
+        s3AccessKey: "access"
+        s3SecretKey: "secret"
+    asserts:
+      - failedTemplate:
+          errorMessage: "backup.destinationPath must name a bucket (s3://bucket/path/) when bootstrap.enabled is true"
+
+  - it: does not check the bucket when bootstrap is disabled
+    release:
+      name: test-mongodb
+      namespace: tenant-test
+    set:
+      bootstrap:
+        enabled: false
+      backup:
+        destinationPath: "s3://"
+    asserts:
+      - hasDocuments:
+          count: 0
+
   #####################
   # PITR              #
   #####################