diff --git a/zsh/.zshrc b/zsh/.zshrc
index c3d1c85..150d350 100644
--- a/zsh/.zshrc
+++ b/zsh/.zshrc
@@ -3,7 +3,7 @@
 # Copyright 2022 Inference
 # License: BSD 3-Clause Clear
 
-# 0.0.0.1
+# 0.2.0.3
 
 
 # Prompt.
@@ -28,6 +28,15 @@ HISTFILE=~/.zsh-history
 HISTSIZE=1024
 SAVEHIST=1024
 
+# XDG_RUNTIME_DIR.
+if test -z "${XDG_RUNTIME_DIR}"; then
+    export XDG_RUNTIME_DIR=/tmp/${UID}-runtime-dir
+    if ! test -d "${XDG_RUNTIME_DIR}"; then
+        mkdir "${XDG_RUNTIME_DIR}"
+        chmod 0700 "${XDG_RUNTIME_DIR}"
+    fi
+fi
+
 # Aliases.
 if [[ -f ~/.zsh-aliases ]]; then
     . ~/.zsh-aliases