diff --git a/nix/base-system/.zshrc b/nix/base-system/.zshrc
index 31a4c7f..9cd6109 100644
--- a/nix/base-system/.zshrc
+++ b/nix/base-system/.zshrc
@@ -35,3 +35,8 @@ function kill_service_on_port() {
         kill -9 $p;
     done
 }
+
+function disk_usage() {
+    local path=${1:-.}
+    /run/current-system/sw/bin/du --max-depth=1 -h "${path}" 2>/dev/null
+}