diff --git a/lib/strings.nix b/lib/strings.nix
index bad8f53fa565..d3ef748fb71e 100644
--- a/lib/strings.nix
+++ b/lib/strings.nix
@@ -350,7 +350,7 @@ rec {
 
      Example:
        ''
-         ${toShellVar foo "some string"}
+         ${toShellVar "foo" "some string"}
          [[ "$foo" == "some string" ]]
        ''
   */