diff --git a/packages/app/e2e/regression/tabs.spec.ts b/packages/app/e2e/regression/tabs.spec.ts
index 647ce37da15..88bf9d83618 100644
--- a/packages/app/e2e/regression/tabs.spec.ts
+++ b/packages/app/e2e/regression/tabs.spec.ts
@@ -1191,6 +1191,26 @@ test("tab shortcuts cycle side-panel tabs when the side panel is focused with mu
   await expectPath(page, sessionHref(beta.id))
 })
 
+test("⌘W past the side panel's last tab keeps the session tab", async ({ page }) => {
+  const sessions = await emptySidePanel(page)
+  await page.keyboard.press("ControlOrMeta+w")
+
+  // From the composer ⌘W closes the session tab, so only a swallowed press above leaves Beta to land on.
+  await page.getByRole("textbox", { name: "Prompt", exact: true }).click()
+  await page.keyboard.press("ControlOrMeta+w")
+  await expectPath(page, sessionHref(sessions.beta.id))
+  await expect(sessions.alphaTab).toHaveCount(0)
+})
+
+test("⌘W closes the session tab again once the window loses focus after the side panel empties", async ({ page }) => {
+  const sessions = await emptySidePanel(page)
+  // ⌘Tab away and back sends no click or key the page sees.
+  await page.evaluate(() => window.dispatchEvent(new Event("blur")))
+  await page.keyboard.press("ControlOrMeta+w")
+  await expectPath(page, sessionHref(sessions.beta.id))
+  await expect(sessions.alphaTab).toHaveCount(0)
+})
+
 // Windows has no native menu bar: the titlebar menu owns Paste, which only the desktop edit action can perform.
 test("the Windows titlebar menu pastes through the desktop edit action", async ({ page }) => {
   await mockWorkspace(page, { name: "WindowsMenu", sessions: [] })
@@ -1279,3 +1299,37 @@ test("loads a tab's transcript while the pointer rests on it, and not when it pa
   await expect(message(b.id)).toBeVisible()
   expect(requested.filter((id) => id === b.id)).toHaveLength(1)
 })
+
+// Closes Alpha's side tabs with ⌘W until the side panel empties and collapses, as an overshooting hand would.
+async function emptySidePanel(page: Page) {
+  await page.setViewportSize({ width: 1440, height: 900 })
+  const directory = "C:/OpenCode/SideCloseOvershoot"
+  const alpha = { id: "ses_side_close_alpha", title: "Side close alpha" }
+  const beta = { id: "ses_side_close_beta", title: "Side close beta" }
+  await openSession(page, {
+    name: "SideCloseOvershoot",
+    sessions: [alpha, beta],
+    fileList: (path) => (path ? [] : ["README.md"].map((file) => fileNode(directory, file))),
+    fileContent: (path) => ({ type: "text", content: `contents:${path}` }),
+    seed: {
+      panes: { [alpha.id]: { review: true }, [beta.id]: { review: true } },
+      storage: reviewTabs(directory, alpha.id),
+    },
+  })
+
+  const panel = page.locator("#review-panel")
+  const reviewTab = panel.getByRole("tab", { name: "Review", exact: true })
+  const fileTab = panel.getByRole("tab", { name: "README.md", exact: true })
+
+  await openFileLauncher(panel)
+  await panel.getByRole("treeitem", { name: "README.md", exact: true }).click()
+  await expect(fileTab).toHaveAttribute("aria-selected", "true")
+  await panel.getByText("contents:README.md", { exact: true }).click()
+  await page.keyboard.press("ControlOrMeta+w")
+  await expect(fileTab).toHaveCount(0)
+  await expect(reviewTab).toHaveAttribute("aria-selected", "true")
+  await page.keyboard.press("ControlOrMeta+w")
+  await expect(panel).toHaveAttribute("aria-hidden", "true")
+
+  return { beta, alphaTab: page.locator(`[data-titlebar-tab-slot]:has(a[href="${sessionHref(alpha.id)}"])`) }
+}
diff --git a/packages/app/src/session/commands/use-session-commands.tsx b/packages/app/src/session/commands/use-session-commands.tsx
index 3b3deb090f7..b040fad3519 100644
--- a/packages/app/src/session/commands/use-session-commands.tsx
+++ b/packages/app/src/session/commands/use-session-commands.tsx
@@ -1,3 +1,5 @@
+import { createEffect, createSignal, on } from "solid-js"
+import { createEventListener } from "@solid-primitives/event-listener"
 import { useCommand, type CommandOption } from "@/shell/commands/command"
 import { adjacentTabKey } from "@/shell/titlebar/tab-order"
 import { useDialog } from "@opencode/ui/context/dialog"
@@ -81,6 +83,27 @@ export const useSessionCommands = (actions: SessionCommandContext) => {
   const inSide = actions.region.focus
   // ⌘T and ⌘W inside the side region open and close its tabs, unless the focused panel binds the key itself there.
   const sideKey = (event: KeyboardEvent) => inSide(event) && !extensionClaims(event)
+  // ⌘W on the side panel's last tab closes the panel and moves focus out of it, where one press too many would close
+  // the session tab. Until the user moves on, by clicking, focusing, another key, or another session, ⌘W closes nothing.
+  // The close moves focus synchronously, before this is set, so its own focusin does not clear it.
+  const [emptied, setEmptied] = createSignal(false)
+  const resetEmptied = () => setEmptied(false)
+  createEventListener(document, ["pointerdown", "focusin"], resetEmptied, { capture: true })
+  createEventListener(window, "blur", resetEmptied)
+  createEventListener(
+    document,
+    "keydown",
+    (event) => {
+      if (["Meta", "Control", "Shift", "Alt"].includes(event.key)) return
+      if (!command.matches("file.close", event)) resetEmptied()
+    },
+    { capture: true },
+  )
+  createEffect(
+    on(() => [actions.session.layout.tabKey(), actions.session.layout.view().side.opened()], resetEmptied, {
+      defer: true,
+    }),
+  )
   const cycleSideTabs = () => actions.session.layout.view().side.opened() && actions.region.keys().length > 1
 
   const sideFocused = (target: EventTarget | null) => {
@@ -404,15 +427,18 @@ export const useSessionCommands = (actions: SessionCommandContext) => {
         slash: "open",
         onSelect: openFile,
       }),
-      side &&
-        fileCommand({
-          id: "file.close",
-          title: language.t("command.tab.close"),
-          keybind: settings.keybinds.get("tab.close") ?? "mod+w",
-          hidden: !tab,
-          when: sideKey,
-          onSelect: closeTab,
-        }),
+      fileCommand({
+        id: "file.close",
+        title: language.t("command.tab.close"),
+        keybind: settings.keybinds.get("tab.close") ?? "mod+w",
+        hidden: !tab,
+        when: (event) => (side ? sideKey(event) : emptied()),
+        onSelect: (source) => {
+          if (!side) return
+          closeTab()
+          setEmptied(source === "keybind" && !actions.session.layout.view().side.opened())
+        },
+      }),
       side &&
         fileCommand({
           id: "file.tab.new",