diff --git a/concepts/labels.mdx b/concepts/labels.mdx
index 3f14e001..7e46e880 100644
--- a/concepts/labels.mdx
+++ b/concepts/labels.mdx
@@ -133,7 +133,9 @@ file; the name of a file is its pathname relative to the directory containing
 the `BUILD` file.
 
 Target names must be composed entirely of characters drawn from the set `a`–`z`,
-`A`–`Z`, `0`–`9`, and the punctuation symbols `!%-@^_"#$&'()*-+,;<=>?[]{|}~/.`.
+`A`–`Z`, `0`–`9`, and the punctuation symbols
+``! \"#$%&'()*+,-./;<=>?@[]^_`{|}~`` (yes, space is allowed, as source files in
+packages may contain spaces). Non-ASCII characters are also permitted.
 
 Filenames must be relative pathnames in normal form, which means they must
 neither start nor end with a slash (for example, `/foo` and `foo/` are
diff --git a/upstream b/upstream
index 5c8f44dd..4440c475 160000
--- a/upstream
+++ b/upstream
@@ -1 +1 @@
-Subproject commit 5c8f44dd387d92886c2ef7aabee03152f9143e73
+Subproject commit 4440c475c90200748aa7f159cbaf10b59ca185bf