diff --git a/nix/packages/by-name/tmux-sessionizer/package.nix b/nix/packages/by-name/tmux-sessionizer/package.nix
index c6e22fa9..d222db0b 100644
--- a/nix/packages/by-name/tmux-sessionizer/package.nix
+++ b/nix/packages/by-name/tmux-sessionizer/package.nix
@@ -2,6 +2,7 @@
   writeShellApplication,
   tmux,
   procps,
+  lib,
   symlinkJoin,
 }: let
   tmux-register-session = writeShellApplication {
@@ -9,6 +10,12 @@
     runtimeInputs = [tmux];
     text = ''
       last=/tmp/TMUX_LAST
+
+      # bail if tmux not running
+      if ! pgrep tmux >/dev/null 2>&1; then
+        exit 1
+      fi
+
       this="$(tmux display-message -p '#S')"
       if [ ! -f "$last" ] || [ "$(cat "$last")" != "$this" ]; then
           echo "$this" >"$last"
@@ -43,6 +50,28 @@
       fi
     '';
   };
+
+  tmux-last = writeShellApplication {
+    name = "tmux-last";
+    text = ''
+      tmux_last=/tmp/TMUX_LAST
+      if [ ! -f $tmux_last ]; then
+          echo "Last session is not yet set"
+          return 1
+      fi
+
+      session_name="$(cat $tmux_last)"
+      session_path="$session_name"
+      if [ ! -d "$session_path" ]; then
+        session_path="/tmp"
+      fi
+
+      # bail if not in tmux, nothing to register
+      ${lib.getExe tmux-register-session} || :
+      ${lib.getExe tmux-maybe-create} "$session_name" "$session_path"
+      ${lib.getExe tmux-attach-or-switch} "$session_name"
+    '';
+  };
 in
   symlinkJoin {
     name = "tmux-sessionizer";
@@ -50,5 +79,6 @@ in
       tmux-register-session
       tmux-maybe-create
       tmux-attach-or-switch
+      tmux-last
     ];
   }