diff --git a/compute_tools/src/compute.rs b/compute_tools/src/compute.rs
index 29b0225419..24b31b132d 100644
--- a/compute_tools/src/compute.rs
+++ b/compute_tools/src/compute.rs
@@ -897,31 +897,28 @@ impl ComputeNode {
         let mut client = config.connect(NoTls)?;
         let pageserver_connect_micros = start_time.elapsed().as_micros() as u64;
 
-        let replica = if spec.spec.mode != ComputeMode::Primary {
-            " --replica"
-        } else {
-            ""
-        };
-        let lazy_slru_download = if spec
+        let tenant_id = spec.tenant_id.to_string();
+        let timeline_id = spec.timeline_id.to_string();
+        let lsn_str = lsn.to_string();
+        let mut cmd = Vec::new();
+        cmd.push("basebackup");
+        cmd.push(&tenant_id);
+        cmd.push(&timeline_id);
+        if lsn != Lsn::INVALID {
+            cmd.push(&lsn_str);
+        }
+        cmd.push("--zip");
+        if spec.spec.mode != ComputeMode::Primary {
+            cmd.push("--replica");
+        }
+        if spec
             .spec
             .features
             .contains(&ComputeFeature::LazySlruDownload)
         {
-            " --lazy-slru-download"
-        } else {
-            ""
-        };
-        let basebackup_cmd = match lsn {
-            Lsn(0) => format!(
-                "basebackup {} {} --gzip{}{}",
-                spec.tenant_id, spec.timeline_id, replica, lazy_slru_download
-            ),
-            _ => format!(
-                "basebackup {} {} {} --gzip{}{}",
-                spec.tenant_id, spec.timeline_id, lsn, replica, lazy_slru_download
-            ),
-        };
-
+            cmd.push("--lazy-slru-download")
+        }
+        let basebackup_cmd = cmd.join(" ");
         let copyreader = client.copy_out(basebackup_cmd.as_str())?;
         let mut measured_reader = MeasuredReader::new(copyreader);
         let mut bufreader = std::io::BufReader::new(&mut measured_reader);