diff --git a/packaging/linux/AppRun b/packaging/linux/AppRun
index d3f6117e..36e0d211 100755
--- a/packaging/linux/AppRun
+++ b/packaging/linux/AppRun
@@ -8,7 +8,8 @@
 # (and whenever the AppImage's path changes) install the .desktop entry and the
 # hicolor icons into $XDG_DATA_HOME, then launch. Every failure here must leave
 # the launch untouched. AppImage managers can opt out with DESKTOPINTEGRATION=1,
-# and users with ARTCRAFT_LAUNCHER_NO_DESKTOP_INTEGRATION=1.
+# and users with ARTCRAFT_LAUNCHER_NO_DESKTOP_INTEGRATION=1. Nothing is installed
+# while another entry (appimaged, AppImageLauncher, Gear Lever) runs this AppImage.
 
 set -u
 
@@ -38,10 +39,17 @@ integrate() {
   data="${XDG_DATA_HOME:-$home/.local/share}"
   src_desktop="$APPDIR/usr/share/applications/$DESK_ID.desktop"
   [ -f "$src_desktop" ] || return 0
+  apps="$data/applications"
+  # A second entry would list the app twice; drop the one we wrote if it is unchanged.
+  if other_entry_runs "$apps" "$appimage"; then
+    if own_entry "$apps/$DESK_ID.desktop" && rm -f "$apps/$DESK_ID.desktop"; then
+      command -v update-desktop-database >/dev/null 2>&1 && update-desktop-database "$apps" >/dev/null 2>&1
+    fi
+    return 0
+  fi
 
   # Rewrite Exec to this AppImage (the binary is not on the host PATH) and drop
   # TryExec, which would hide the entry; everything else is shipped as packaged.
-  apps="$data/applications"
   mkdir -p "$apps" 2>/dev/null || return 0
   tmp="$apps/.$DESK_ID.tmp.$$"
   esc="$(printf '%s' "$appimage" | sed 's/[\\&|]/\\&/g')"
@@ -97,7 +105,36 @@ own_entry() {
   [ "$existing_exec" = "$generated_exec" ] || return 1
   expected_body="$(sed -e '/^Exec=/d' -e '/^TryExec=/d' "$src_desktop")" || return 1
   existing_body="$(sed -e '/^Exec=/d' -e '/^X-ArtCraft-Launcher-Generated-Exec=/d' "$1")" || return 1
-  [ "$expected_body" = "$existing_body" ]
+  # Entries written before the StartupWMClass fix differ only in that line.
+  old_body="$(printf '%s\n' "$expected_body" | sed 's/^StartupWMClass=.*/StartupWMClass=artcraft-launcher/')"
+  [ "$expected_body" = "$existing_body" ] || [ "$old_body" = "$existing_body" ]
+}
+
+# True when a visible entry in $1 other than ours runs the AppImage $2 and has our window class.
+other_entry_runs() {
+  grep -lF -e "$2" "$1"/*.desktop 2>/dev/null | (
+    while IFS= read -r f; do
+      [ "$f" = "$1/$DESK_ID.desktop" ] && continue
+      main=false runs=false class=false
+      while IFS= read -r line || [ -n "$line" ]; do
+        # Only the [Desktop Entry] group; an action's Exec isn't what the entry launches.
+        case "$line" in
+          "[Desktop Entry]") main=true && continue ;;
+          "["*) main=false ;;
+        esac
+        [ "$main" = true ] || continue
+        case "$line" in
+          # Menu editors hide an entry this way; it lists nothing.
+          Hidden=true | NoDisplay=true) runs=false && break ;;
+          # A class from before an in-place update can't match the window, so ours has to stay.
+          "StartupWMClass=$DESK_ID") class=true ;;
+          Exec=*"$2" | Exec=*"$2 "* | Exec=*"$2\""* | Exec=*"$2'"*) runs=true ;;
+        esac
+      done <"$f"
+      [ "$runs" = true ] && [ "$class" = true ] && exit 0
+    done
+    exit 1
+  )
 }
 
 integrate
diff --git a/packaging/linux/apprun-test.sh b/packaging/linux/apprun-test.sh
index 28c9890f..9eb4837b 100755
--- a/packaging/linux/apprun-test.sh
+++ b/packaging/linux/apprun-test.sh
@@ -181,4 +181,64 @@ ln -s "$TMP/manager-entry" "$DESKTOP"
 "$APPDIR/AppRun" >/dev/null || fail "launch with desktop symlink failed"
 [[ -L "$DESKTOP" ]] || fail "desktop symlink replaced"
 
+# 15. appimaged lists this AppImage under its own name: drop our entry, install nothing more.
+rm -rf "$XDG_DATA_HOME"
+"$APPDIR/AppRun" >/dev/null || fail "launch before appimaged failed"
+apps="$XDG_DATA_HOME/applications"
+real="$(readlink -f "$APPIMAGE")"
+printf '[Desktop Entry]\nName=ArtCraft Launcher\nExec="/usr/bin/appimaged" wrap "%s" %%F\nStartupWMClass=%s\nActions=Trash;\n\n[Desktop Action Trash]\nName=Move to Trash\nExec=gio trash "%s"\n' "$real" "$APP_ID" "$real" >"$apps/appimagekit_0123abcd.desktop"
+rm -rf "$XDG_DATA_HOME/icons"
+out="$("$APPDIR/AppRun" managed)" || fail "launch beside appimaged failed"
+[[ "$out" = "stub: managed" ]] || fail "launch beside appimaged lost arguments"
+[[ ! -e "$DESKTOP" ]] || fail "own entry kept beside appimaged's"
+[[ ! -e "$XDG_DATA_HOME/icons" ]] || fail "icons installed beside appimaged's entry"
+
+# 15a. Gear Lever's entry (single-quoted path, no trailing newline) counts too.
+rm -rf "$XDG_DATA_HOME" && mkdir -p "$apps"
+spaced="$TMP/Art Craft.AppImage"
+: >"$spaced"
+printf "[Desktop Entry]\nName=ArtCraft Launcher\nStartupWMClass=%s\nExec=env DESKTOPINTEGRATION=1 '%s'" "$APP_ID" "$(readlink -f "$spaced")" >"$apps/artcraft_launcher.desktop"
+APPIMAGE="$spaced" "$APPDIR/AppRun" >/dev/null || fail "launch beside Gear Lever failed"
+[[ ! -e "$DESKTOP" ]] || fail "integrated beside Gear Lever's entry"
+
+# 15b. Our entry with user changes stays beside a manager's entry.
+cp "$apps/artcraft_launcher.desktop" "$TMP/gear-lever-entry"
+sed "s|^Exec=.*|Exec=\"$(readlink -f "$APPIMAGE")\"|" "$TMP/gear-lever-entry" >"$apps/artcraft_launcher.desktop"
+sed 's/^Name=.*/Name=My Launcher/' "$TMP/generated-entry" >"$DESKTOP"
+cp "$DESKTOP" "$TMP/renamed-entry"
+"$APPDIR/AppRun" >/dev/null || fail "launch with renamed entry failed"
+cmp -s "$DESKTOP" "$TMP/renamed-entry" || fail "user-changed entry removed"
+
+# 15c. An entry for another file that shares our path as a prefix doesn't count.
+rm -rf "$XDG_DATA_HOME" && mkdir -p "$apps"
+printf '[Desktop Entry]\nStartupWMClass=%s\nExec="%s.old"\n' "$APP_ID" "$(readlink -f "$APPIMAGE")" >"$apps/old-copy.desktop"
+"$APPDIR/AppRun" >/dev/null || fail "launch beside an older copy's entry failed"
+[[ -f "$DESKTOP" ]] || fail "an entry for another file blocked integration"
+
+# 15d. An entry from a release with the old StartupWMClass is ours: refreshed, and dropped beside appimaged's.
+sed 's/^StartupWMClass=.*/StartupWMClass=artcraft-launcher/' "$TMP/generated-entry" >"$DESKTOP"
+"$APPDIR/AppRun" >/dev/null || fail "launch over an older release's entry failed"
+cmp -s "$DESKTOP" "$TMP/generated-entry" || fail "older release's entry not refreshed"
+sed 's/^StartupWMClass=.*/StartupWMClass=artcraft-launcher/' "$TMP/generated-entry" >"$DESKTOP"
+printf '[Desktop Entry]\nExec="/usr/bin/appimaged" wrap "%s" %%F\nStartupWMClass=%s\n' "$real" "$APP_ID" >"$apps/appimagekit_0123abcd.desktop"
+"$APPDIR/AppRun" >/dev/null || fail "launch over an older release's entry beside appimaged failed"
+[[ ! -e "$DESKTOP" ]] || fail "older release's entry kept beside appimaged's"
+
+# 15e. A manager's entry hidden with a menu editor lists nothing: ours is installed and kept.
+for key in NoDisplay Hidden; do
+  printf '[Desktop Entry]\nExec="/usr/bin/appimaged" wrap "%s" %%F\nStartupWMClass=%s\n%s=true\n' "$real" "$APP_ID" "$key" >"$apps/appimagekit_0123abcd.desktop"
+  "$APPDIR/AppRun" >/dev/null || fail "launch beside a hidden entry failed"
+  [[ -f "$DESKTOP" ]] || fail "no entry of ours beside a $key=true manager entry"
+done
+
+# 15f. A manager's entry left with the old window class by an in-place update: ours stays.
+printf '[Desktop Entry]\nExec="/usr/bin/appimaged" wrap "%s" %%F\nStartupWMClass=artcraft-launcher\n' "$real" >"$apps/appimagekit_0123abcd.desktop"
+"$APPDIR/AppRun" >/dev/null || fail "launch beside an old-class manager entry failed"
+[[ -f "$DESKTOP" ]] || fail "own entry dropped beside a manager entry with the old class"
+
+# 15g. Only the [Desktop Entry] group counts: an action that runs this AppImage doesn't.
+printf '[Desktop Entry]\nExec=other-app\nStartupWMClass=%s\nActions=Launcher;\n\n[Desktop Action Launcher]\nExec="%s"\n' "$APP_ID" "$real" >"$apps/appimagekit_0123abcd.desktop"
+"$APPDIR/AppRun" >/dev/null || fail "launch beside an entry that runs this AppImage from an action failed"
+[[ -f "$DESKTOP" ]] || fail "own entry dropped beside an entry that runs this AppImage only from an action"
+
 echo "AppRun desktop integration ok"