diff --git a/electron/main/backend/install-manager.ts b/electron/main/backend/install-manager.ts
index 21a11037..d2dad6e3 100644
--- a/electron/main/backend/install-manager.ts
+++ b/electron/main/backend/install-manager.ts
@@ -148,8 +148,7 @@ ipcMain.on("queue-install", async (event, download_json) => {
     typeof download_json === "string"
       ? JSON.parse(download_json)
       : download_json;
-  const { id, pkgname, metalinkUrl, filename, upgradeOnly, origin } =
-    download || {};
+  const { id, pkgname, metalinkUrl, filename, origin } = download || {};
 
   if (!id || !pkgname) {
     logger.warn("passed arguments missing id or pkgname");
@@ -249,26 +248,24 @@ ipcMain.on("queue-install", async (event, download_json) => {
   }
 
   if (origin === "spark") {
-    // Spark Store logic
-    if (upgradeOnly) {
-      execCommand = superUserCmd || SHELL_CALLER_PATH;
-      if (superUserCmd) execParams.push(SHELL_CALLER_PATH);
-      execParams.push("aptss", "install", "-y", pkgname, "--only-upgrade");
-    } else {
-      execCommand = superUserCmd || SHELL_CALLER_PATH;
-      if (superUserCmd) execParams.push(SHELL_CALLER_PATH);
+    execCommand = superUserCmd || SHELL_CALLER_PATH;
+    if (superUserCmd) execParams.push(SHELL_CALLER_PATH);
 
-      if (metalinkUrl && filename) {
-        execParams.push(
-          "ssinstall",
-          `${downloadDir}/${filename}`,
-          "--delete-after-install",
-          "--no-create-desktop-entry",
-          "--native",
-        );
-      } else {
-        execParams.push("aptss", "install", "-y", pkgname);
-      }
+    if (metalinkUrl && filename) {
+      execParams.push(
+        "ssinstall",
+        `${downloadDir}/${filename}`,
+        "--delete-after-install",
+        "--no-create-desktop-entry",
+        "--native",
+      );
+    } else {
+      execParams.push(
+        "ssinstall",
+        pkgname,
+        "--no-create-desktop-entry",
+        "--native",
+      );
     }
   } else {
     // APM Store logic
diff --git a/src/__tests__/unit/update-center/task-runner.test.ts b/src/__tests__/unit/update-center/task-runner.test.ts
index eaf5831c..daaa783d 100644
--- a/src/__tests__/unit/update-center/task-runner.test.ts
+++ b/src/__tests__/unit/update-center/task-runner.test.ts
@@ -3,7 +3,6 @@ import { describe, expect, it, vi } from "vitest";
 import type { UpdateCenterItem } from "../../../../electron/main/backend/update-center/types";
 import {
   createTaskRunner,
-  buildLegacySparkUpgradeCommand,
   installUpdateItem,
 } from "../../../../electron/main/backend/update-center/install";
 import { createUpdateCenterQueue } from "../../../../electron/main/backend/update-center/queue";
@@ -114,22 +113,6 @@ describe("update-center task runner", () => {
     });
   });
 
-  it("returns a direct aptss upgrade command instead of spark-update-tool", () => {
-    expect(
-      buildLegacySparkUpgradeCommand("spark-weather", "/usr/bin/pkexec"),
-    ).toEqual({
-      execCommand: "/usr/bin/pkexec",
-      execParams: [
-        "/opt/spark-store/extras/shell-caller.sh",
-        "aptss",
-        "install",
-        "-y",
-        "spark-weather",
-        "--only-upgrade",
-      ],
-    });
-  });
-
   it("blocks close while a refresh or task is still running", () => {
     const queue = createUpdateCenterQueue();
     const item = createAptssItem();
@@ -208,7 +191,7 @@ describe("update-center task runner", () => {
         {
           id: task.id,
           status: "failed",
-          error: "APM update task requires downloaded package metadata",
+          error: "Update task for spark-player requires download metadata (URL and filename)",
         },
       ],
     });
@@ -300,4 +283,28 @@ describe("update-center task runner", () => {
       },
     ]);
   });
+
+  it("uses ssinstall for aptss (spark) file installs", async () => {
+    childProcessMock.spawnCalls.length = 0;
+
+    await installUpdateItem({
+      item: createAptssItem(),
+      filePath: "/tmp/spark-weather.deb",
+      superUserCmd: "/usr/bin/pkexec",
+    });
+
+    expect(childProcessMock.spawnCalls).toEqual([
+      {
+        command: "/usr/bin/pkexec",
+        args: [
+          "/opt/spark-store/extras/shell-caller.sh",
+          "ssinstall",
+          "/tmp/spark-weather.deb",
+          "--delete-after-install",
+          "--no-create-desktop-entry",
+          "--native",
+        ],
+      },
+    ]);
+  });
 });
diff --git a/src/components/DownloadDetail.vue b/src/components/DownloadDetail.vue
index db27ab70..f449d995 100644
--- a/src/components/DownloadDetail.vue
+++ b/src/components/DownloadDetail.vue
@@ -13,7 +13,7 @@
       @click="handleOverlayClick"
     >
       <div
-        class="scrollbar-nowidth scrollbar-thumb-slate-200 dark:scrollbar-thumb-slate-700 scrollbar-track-transparent w-full max-w-2xl max-h-[85vh] overflow-y-auto rounded-3xl border border-white/10 bg-white/95 p-6 shadow-2xl dark:border-slate-800 dark:bg-slate-900"
+        class="scrollbar-nowidth scrollbar-thumb-slate-200 dark:scrollbar-thumb-slate-700 scrollbar-track-transparent w-full max-w-2xl max-h-[85vh] overflow-y-auto overscroll-contain rounded-3xl border border-white/10 bg-white/95 p-6 shadow-2xl dark:border-slate-800 dark:bg-slate-900"
         @click.stop
       >
         <div class="flex items-start justify-between">
@@ -154,7 +154,7 @@
               </button>
             </div>
             <div
-              class="max-h-48 space-y-2 overflow-y-auto rounded-2xl bg-slate-50/80 p-3 font-mono text-xs text-slate-600 dark:bg-slate-900/60 dark:text-slate-300"
+              class="max-h-48 space-y-2 overflow-y-auto overscroll-contain rounded-2xl bg-slate-50/80 p-3 font-mono text-xs text-slate-600 dark:bg-slate-900/60 dark:text-slate-300"
             >
               <div
                 v-for="(log, index) in download.logs"
diff --git a/src/components/DownloadQueue.vue b/src/components/DownloadQueue.vue
index 41ef9c00..e094a507 100644
--- a/src/components/DownloadQueue.vue
+++ b/src/components/DownloadQueue.vue
@@ -49,7 +49,7 @@
       leave-from-class="opacity-100 translate-y-0"
       leave-to-class="opacity-0 -translate-y-2"
     >
-      <div v-show="isExpanded" class="max-h-96 overflow-y-auto px-3 pb-4">
+      <div v-show="isExpanded" class="max-h-96 overflow-y-auto overscroll-contain px-3 pb-4">
         <div
           v-if="downloads.length === 0"
           class="flex flex-col items-center justify-center rounded-2xl border border-dashed border-slate-200/80 px-4 py-12 text-slate-500 dark:border-slate-800/80 dark:text-slate-400"