diff --git a/README.md b/README.md
index dc31360..a7eb8a2 100644
--- a/README.md
+++ b/README.md
@@ -17,7 +17,7 @@ nix run .#package          # pure store binary
 nix run .#package-desktop  # pure package via its .desktop
 ```
 
-`apps.default` / `apps.desktop` use the **devshell toolchain** (`rustc`/`cargo` + egui libs), stage `usage.desktop` + hicolor icons under `.desktop-share/`, then `gtk-launch usage` so the **app icon** applies. Incremental builds go into `./target/`.
+`apps.default` / `apps.desktop` cargo-build, install `usage.desktop` + hicolor icons into **`$XDG_DATA_HOME`** (`~/.local/share` by default — required on Wayland/GNOME; a private share dir is invisible to the shell), refresh icon/desktop caches, then `gtk-launch usage`. The binary also embeds the PNG via `vidya::with_app_icon_id` (used on X11; Wayland window icons come from the FreeDesktop entry). Incremental builds go into `./target/`.
 
 Optional interactive shell:
 
diff --git a/flake.nix b/flake.nix
index bfdcf74..a0efa87 100644
--- a/flake.nix
+++ b/flake.nix
@@ -59,19 +59,32 @@
         fi
       '';
 
-      # Stage FreeDesktop share tree (icon + .desktop) for gtk-launch (shell, not nix-build).
-      installDesktopShare = shareDir: execPath: ''
-        mkdir -p "${shareDir}/applications"
-        mkdir -p "${shareDir}/icons/hicolor/scalable/apps"
-        cp assets/usage.svg "${shareDir}/icons/hicolor/scalable/apps/usage.svg"
+      # Install FreeDesktop entry + hicolor icons under a share root (usually
+      # $XDG_DATA_HOME). Wayland compositors (GNOME) look up icons by app_id via
+      # the *session* data dirs — a temporary XDG_DATA_DIRS on the child alone
+      # is not enough. Absolute Icon= path is the reliable dock/overview path.
+      # Shell fragment: $1=shareDir $2=execPath (absolute).
+      installDesktopShareSh = ''
+        _share="$1"
+        _exec="$2"
+        _icon="$_share/icons/hicolor/256x256/apps/usage.png"
+        mkdir -p "$_share/applications"
+        mkdir -p "$_share/icons/hicolor/scalable/apps"
+        cp assets/usage.svg "$_share/icons/hicolor/scalable/apps/usage.svg"
         for sz in 16 24 32 48 64 128 256; do
-          mkdir -p "${shareDir}/icons/hicolor/''${sz}x''${sz}/apps"
+          mkdir -p "$_share/icons/hicolor/''${sz}x''${sz}/apps"
           rsvg-convert -w "$sz" -h "$sz" assets/usage.svg \
-            -o "${shareDir}/icons/hicolor/''${sz}x''${sz}/apps/usage.png"
+            -o "$_share/icons/hicolor/''${sz}x''${sz}/apps/usage.png"
         done
-        # @EXEC@ is a placeholder in usage.desktop (substitute is nix-build only).
-        sed "s|@EXEC@|${execPath}|g" usage.desktop \
-          > "${shareDir}/applications/usage.desktop"
+        sed -e "s|@EXEC@|''${_exec}|g" -e "s|@ICON@|''${_icon}|g" usage.desktop \
+          > "$_share/applications/usage.desktop"
+        # Help icon themes / menus pick up the new files this session.
+        if command -v gtk-update-icon-cache >/dev/null 2>&1; then
+          gtk-update-icon-cache -f "$_share/icons/hicolor" 2>/dev/null || true
+        fi
+        if command -v update-desktop-database >/dev/null 2>&1; then
+          update-desktop-database "$_share/applications" 2>/dev/null || true
+        fi
       '';
     in
     {
@@ -119,7 +132,8 @@
 
               install -d $out/share/applications
               substitute ${./usage.desktop} $out/share/applications/usage.desktop \
-                --replace-fail '@EXEC@' "$out/bin/usage"
+                --replace-fail '@EXEC@' "$out/bin/usage" \
+                --replace-fail '@ICON@' "$out/share/icons/hicolor/256x256/apps/usage.png"
             '';
 
             meta = {
@@ -131,13 +145,27 @@
             };
           };
 
-          # gtk-launch the packaged .desktop (store binary + icon).
+          # Install store .desktop+icons into the user data home, then gtk-launch.
+          # (GNOME Shell only resolves icons from session-known data dirs.)
           desktop = pkgs.writeShellApplication {
             name = "usage-desktop";
-            runtimeInputs = [ pkgs.gtk3 ];
+            runtimeInputs = [
+              pkgs.gtk3
+              pkgs.desktop-file-utils
+            ];
             text = ''
               set -euo pipefail
-              export XDG_DATA_DIRS="${usage}/share''${XDG_DATA_DIRS:+:$XDG_DATA_DIRS}"
+              DATA_HOME="''${XDG_DATA_HOME:-$HOME/.local/share}"
+              mkdir -p "$DATA_HOME/applications" "$DATA_HOME/icons/hicolor"
+              cp -a ${usage}/share/icons/hicolor/. "$DATA_HOME/icons/hicolor/"
+              ICON="$DATA_HOME/icons/hicolor/256x256/apps/usage.png"
+              sed -e "s|^Exec=.*|Exec=${usage}/bin/usage|" \
+                  -e "s|^Icon=.*|Icon=$ICON|" \
+                ${usage}/share/applications/usage.desktop \
+                > "$DATA_HOME/applications/usage.desktop"
+              gtk-update-icon-cache -f "$DATA_HOME/icons/hicolor" 2>/dev/null || true
+              update-desktop-database "$DATA_HOME/applications" 2>/dev/null || true
+              export XDG_DATA_DIRS="$DATA_HOME''${XDG_DATA_DIRS:+:$XDG_DATA_DIRS}"
               if command -v gtk-launch >/dev/null 2>&1; then
                 exec gtk-launch usage "$@"
               fi
@@ -165,6 +193,7 @@
             pkg-config
             librsvg
             gtk3
+            desktop-file-utils # update-desktop-database
           ];
 
           # Local cargo build (devshell tools; no pure sandbox / remote upload lock).
@@ -192,8 +221,8 @@
             '';
           };
 
-          # Cargo build + stage .desktop/icons into .desktop-share, then gtk-launch.
-          # Primary way to "run the .desktop" from a flake app without a pure rebuild.
+          # Cargo build, install .desktop+icons into XDG_DATA_HOME (so GNOME/Wayland
+          # can resolve Icon= by app_id), then gtk-launch.
           desktopApp = pkgs.writeShellApplication {
             name = "usage-desktop";
             runtimeInputs = cargoTools;
@@ -202,14 +231,27 @@
               echo "→ cargo build --release"
               cargo build --release
 
-              SHARE="''${USAGE_DESKTOP_SHARE:-$PWD/.desktop-share}"
               EXEC="$PWD/target/release/usage"
+              # Session-visible FreeDesktop tree (not a private .desktop-share):
+              # Wayland shells ignore child-only XDG_DATA_DIRS for dock icons.
+              DATA_HOME="''${XDG_DATA_HOME:-$HOME/.local/share}"
+              echo "→ install launcher+icon → $DATA_HOME ({applications,icons}/…)"
+              (
+                set -- "$DATA_HOME" "$EXEC"
+                ${installDesktopShareSh}
+              )
+              # Mirror under .desktop-share for inspection / CI.
+              SHARE="''${USAGE_DESKTOP_SHARE:-$PWD/.desktop-share}"
               rm -rf "$SHARE"
               mkdir -p "$SHARE"
-              ${installDesktopShare "$SHARE" "$EXEC"}
+              (
+                set -- "$SHARE" "$EXEC"
+                ${installDesktopShareSh}
+              )
 
-              export XDG_DATA_DIRS="$SHARE''${XDG_DATA_DIRS:+:$XDG_DATA_DIRS}"
-              echo "→ gtk-launch usage  (Icon=usage, Exec=$EXEC)"
+              export XDG_DATA_DIRS="$DATA_HOME''${XDG_DATA_DIRS:+:$XDG_DATA_DIRS}"
+              ICON="$DATA_HOME/icons/hicolor/256x256/apps/usage.png"
+              echo "→ gtk-launch usage  (Icon=$ICON, Exec=$EXEC, app_id=usage)"
               if command -v gtk-launch >/dev/null 2>&1; then
                 exec gtk-launch usage "$@"
               fi
diff --git a/usage.desktop b/usage.desktop
index 51c7fe1..c15463a 100644
--- a/usage.desktop
+++ b/usage.desktop
@@ -4,7 +4,7 @@ Name=I/O Usage
 GenericName=I/O Gauges
 Comment=Live disk and network throughput gauges
 Exec=@EXEC@
-Icon=usage
+Icon=@ICON@
 Categories=System;Monitor;
 Keywords=io;disk;network;gauge;throughput;vidya;usage;
 Terminal=false