diff --git a/src/nix/ping-store.md b/src/nix/ping-store.md
index 322093091..79b108d9c 100644
--- a/src/nix/ping-store.md
+++ b/src/nix/ping-store.md
@@ -27,4 +27,6 @@ argument `--store` *url*) can be accessed. What this means is
 dependent on the type of the store. For instance, for an SSH store it
 means that Nix can connect to the specified machine.
 
+When the command succeeds a zero exit code is returned with no output.
+
 )""