diff --git a/build/icons/128x128.png b/build/icons/128x128.png
index 4fbb9a35..5f392ce4 100644
Binary files a/build/icons/128x128.png and b/build/icons/128x128.png differ
diff --git a/build/icons/16x16.png b/build/icons/16x16.png
index dcb2ba50..f4092c34 100644
Binary files a/build/icons/16x16.png and b/build/icons/16x16.png differ
diff --git a/build/icons/256x256.png b/build/icons/256x256.png
index f670daba..d0a8448a 100644
Binary files a/build/icons/256x256.png and b/build/icons/256x256.png differ
diff --git a/build/icons/32x32.png b/build/icons/32x32.png
index 27607837..656bfcd3 100644
Binary files a/build/icons/32x32.png and b/build/icons/32x32.png differ
diff --git a/build/icons/48x48.png b/build/icons/48x48.png
index 18542816..235d695f 100644
Binary files a/build/icons/48x48.png and b/build/icons/48x48.png differ
diff --git a/build/icons/512x512.png b/build/icons/512x512.png
index 26afcdab..f513d4c9 100644
Binary files a/build/icons/512x512.png and b/build/icons/512x512.png differ
diff --git a/build/icons/64x64.png b/build/icons/64x64.png
index 0b3ab0db..cee6f4e6 100644
Binary files a/build/icons/64x64.png and b/build/icons/64x64.png differ
diff --git a/electron-builder.config.cjs b/electron-builder.config.cjs
index e85b6ff0..21e59516 100644
--- a/electron-builder.config.cjs
+++ b/electron-builder.config.cjs
@@ -147,10 +147,13 @@ module.exports = {
         shortcutName: 'Netcatty'
     },
     linux: {
-        // Linux desktop icons render full-bleed like Windows — use the
-        // tight-crop source so the app icon doesn't look padded in KDE /
-        // GNOME launchers or AppImage integrations.
-        icon: 'public/icon-win.png',
+        // Linux .deb/.rpm/AppImage icons come from build/icons/* (see
+        // scripts/generate-linux-icons.sh). Point at the icons directory
+        // under buildResources — electron-builder still falls back to the
+        // top-level icon (public/icon.png) when linux.icon is unset, which
+        // installs only hicolor/1024x1024 and launchers miss the icon (#274,
+        // #1340). Do NOT set linux.icon to a single 1024px PNG either.
+        icon: 'icons',
         target: ['AppImage', 'deb', 'rpm'],
         category: 'Development',
         extraResources: [...moshExtraResources('linux'), ...etExtraResources('linux')]
diff --git a/scripts/electron-builder-config.test.cjs b/scripts/electron-builder-config.test.cjs
index f1e3e15e..4614c273 100644
--- a/scripts/electron-builder-config.test.cjs
+++ b/scripts/electron-builder-config.test.cjs
@@ -53,3 +53,37 @@ test("asarUnpack keeps MCP server runtime deps unpacked", () => {
   // @modelcontextprotocol/sdk is now a direct dep and the MCP server hard-requires it.
   assert.ok(config.asarUnpack.includes("node_modules/@modelcontextprotocol/sdk/**/*"));
 });
+
+test("linux packaging uses multi-size build/icons instead of a single 1024px override", async () => {
+  assert.equal(
+    config.linux.icon,
+    "icons",
+    "linux.icon must point at build/icons so electron-builder installs hicolor/* sizes",
+  );
+  assert.equal(config.directories.buildResources, "build");
+
+  const fs = require("node:fs");
+  const path = require("node:path");
+  const iconsDir = path.join(__dirname, "..", "build", "icons");
+  for (const size of [16, 32, 48, 64, 128, 256, 512]) {
+    const file = path.join(iconsDir, `${size}x${size}.png`);
+    assert.ok(fs.existsSync(file), `expected Linux icon: build/icons/${size}x${size}.png`);
+  }
+
+  const { convertIcon } = require("app-builder-lib/out/util/iconConverter");
+  const projectDir = path.join(__dirname, "..");
+  const buildResources = path.join(projectDir, config.directories.buildResources);
+  const sources = [config.linux.icon, config.mac?.icon ?? config.icon].filter(Boolean);
+  const result = await convertIcon({
+    sources,
+    fallbackSources: [buildResources],
+    roots: [buildResources, projectDir],
+    format: "set",
+    outDir: path.join(projectDir, "release", ".icon-config-test"),
+  });
+  const sizes = result.icons.map((icon) => icon.size);
+  assert.ok(
+    sizes.includes(48) && sizes.includes(256) && !sizes.every((size) => size === 1024),
+    `expected standard hicolor sizes, got: ${sizes.join(", ")}`,
+  );
+});
diff --git a/scripts/generate-linux-icons.sh b/scripts/generate-linux-icons.sh
new file mode 100755
index 00000000..08bd72f2
--- /dev/null
+++ b/scripts/generate-linux-icons.sh
@@ -0,0 +1,31 @@
+#!/usr/bin/env bash
+# Generate build/icons/* from public/icon-win.png for Linux packaging.
+# electron-builder installs these into /usr/share/icons/hicolor/<size>/apps/.
+#
+# Requires ImageMagick (`convert`). Run from repo root:
+#   ./scripts/generate-linux-icons.sh
+set -euo pipefail
+
+ROOT="$(cd "$(dirname "$0")/.." && pwd)"
+SOURCE="$ROOT/public/icon-win.png"
+OUT_DIR="$ROOT/build/icons"
+
+if command -v magick >/dev/null 2>&1; then
+  CONVERT=(magick)
+elif command -v convert >/dev/null 2>&1; then
+  CONVERT=(convert)
+else
+  echo "error: ImageMagick is required (magick or convert)" >&2
+  exit 1
+fi
+
+if [[ ! -f "$SOURCE" ]]; then
+  echo "error: source icon not found: $SOURCE" >&2
+  exit 1
+fi
+
+mkdir -p "$OUT_DIR"
+for size in 16 32 48 64 128 256 512; do
+  "${CONVERT[@]}" "$SOURCE" -resize "${size}x${size}!" "$OUT_DIR/${size}x${size}.png"
+  echo "wrote build/icons/${size}x${size}.png"
+done