diff --git a/README.md b/README.md
index b9053a7..acee522 100644
--- a/README.md
+++ b/README.md
@@ -502,6 +502,11 @@ Named context shortcuts (e.g. `dcr`, `dck`) live in `~/.config/.user-dots/fish/l
 
 > [!WARNING]
 > Fish **4.0 or newer is required.** This config uses `test` syntax and other constructs that are incompatible with Fish 3.x. Older versions will produce errors on startup.
+> If you are on an older Fish, you can upgrade via cargo (Fish 4.x is a Rust rewrite published to crates.io):
+> ```
+> cargo install fish
+> ```
+> Or run `fish-deps update` once cargo is available — it will upgrade Fish via cargo automatically.
 
 ### Recommended
 
diff --git a/functions/_fish_deps_catalog.fish b/functions/_fish_deps_catalog.fish
index 5667f11..58105c8 100644
--- a/functions/_fish_deps_catalog.fish
+++ b/functions/_fish_deps_catalog.fish
@@ -25,7 +25,7 @@ function _fish_deps_catalog
         rec rec rec rec rec rec rec rec rec rec rec rec rec rec
 
     set -g _fdc_cargo \
-        "" "" "" starship "" zoxide "" "" \
+        fish "" "" starship "" zoxide "" "" \
         "" "" \
         eza lsd bat "" du-dust "" "" "" ripgrep "" "" trash-cli "" ""
 
diff --git a/functions/_fish_deps_update.fish b/functions/_fish_deps_update.fish
index 35d2b14..eff4cdd 100644
--- a/functions/_fish_deps_update.fish
+++ b/functions/_fish_deps_update.fish
@@ -75,6 +75,11 @@ function _fish_deps_update
             echo "Updating $bin..."
             cargo install --force $cargo_crate
             set updated_any 1
+            if test "$bin" = fish
+                set_color yellow
+                echo "  Fish updated — restart your shell to use the new version."
+                set_color normal
+            end
             set i (math $i + 1)
             continue
         end