diff --git a/pkg/operator/ceph/object/admin.go b/pkg/operator/ceph/object/admin.go
index c9f3ceb4c..b1d262fdd 100644
--- a/pkg/operator/ceph/object/admin.go
+++ b/pkg/operator/ceph/object/admin.go
@@ -60,7 +60,7 @@ func NewMultisiteContext(context *clusterd.Context, clusterInfo *client.ClusterI
 func extractJSON(output string) (string, error) {
 	// `radosgw-admin` sometimes leaves logs to stderr even if it succeeds.
 	// So we should skip them if parsing output as json.
-	pattern := regexp.MustCompile("(?ms)^{.*")
+	pattern := regexp.MustCompile(`(?ms)^{.*}$`)
 	match := pattern.Find([]byte(output))
 	if match == nil {
 		return "", errors.Errorf("didn't contain json. %s", output)
diff --git a/pkg/operator/ceph/object/admin_test.go b/pkg/operator/ceph/object/admin_test.go
index bab789ac1..2c43e81be 100644
--- a/pkg/operator/ceph/object/admin_test.go
+++ b/pkg/operator/ceph/object/admin_test.go
@@ -45,4 +45,10 @@ func TestExtractJson(t *testing.T) {
 	match, err = extractJSON(s)
 	assert.NoError(t, err)
 	assert.True(t, json.Valid([]byte(match)))
+
+	s = `{"test": "test"}
+this line can't be parsed as json`
+	match, err = extractJSON(s)
+	assert.NoError(t, err)
+	assert.True(t, json.Valid([]byte(match)))
 }