diff --git a/nix/packages/by-name/tmux-sessionizer/package.nix b/nix/packages/by-name/tmux-sessionizer/package.nix
index 121ee8db..90a99068 100644
--- a/nix/packages/by-name/tmux-sessionizer/package.nix
+++ b/nix/packages/by-name/tmux-sessionizer/package.nix
@@ -1,6 +1,7 @@
 {
   writeShellApplication,
   tmux,
+  procps,
   symlinkJoin,
 }: let
   tmux-register-session = writeShellApplication {
@@ -14,10 +15,24 @@
       fi
     '';
   };
+
+  tmux-maybe-create = writeShellApplication {
+    name = "__tmux-maybe-create";
+    runtimeInputs = [procps tmux];
+    text = ''
+      session_name="$1"
+      session_dir="$2"
+
+      if ! pgrep tmux >/dev/null 2>&1 || ! tmux has -t="$session_name" 2>/dev/null; then
+          tmux new-session -ds "$session_name" -c "$session_dir"
+      fi
+    '';
+  };
 in
   symlinkJoin {
     name = "tmux-sessionizer";
     paths = [
       tmux-register-session
+      tmux-maybe-create
     ];
   }