diff --git a/src/doc/rustc-dev-guide/ci/sembr/src/main.rs b/src/doc/rustc-dev-guide/ci/sembr/src/main.rs
index 1de0638deb97..0ae77af047e6 100644
--- a/src/doc/rustc-dev-guide/ci/sembr/src/main.rs
+++ b/src/doc/rustc-dev-guide/ci/sembr/src/main.rs
@@ -24,7 +24,7 @@ static REGEX_IGNORE_END: LazyLock<Regex> =
 static REGEX_IGNORE_LINK_TARGETS: LazyLock<Regex> =
     LazyLock::new(|| Regex::new(r"^\[.+\]: ").unwrap());
 static REGEX_SPLIT: LazyLock<Regex> =
-    LazyLock::new(|| Regex::new(r"([^\.\d\-\*]\.|[^r]\?|!)\s").unwrap());
+    LazyLock::new(|| Regex::new(r"([^\.\d\-\*]\.|[^r\~]\?|!)\s").unwrap());
 // list elements, numbered (1.) or not  (- and *)
 static REGEX_LIST_ENTRY: LazyLock<Regex> =
     LazyLock::new(|| Regex::new(r"^\s*(\d\.|\-|\*|\d\))\s+").unwrap());
@@ -205,6 +205,7 @@ git log main.. compiler
 o? whatever
 r? @reviewer
  r? @reviewer
+~? diagnostic
 ";
     let expected = "
 # some. heading
@@ -237,6 +238,7 @@ o?
 whatever
 r? @reviewer
  r? @reviewer
+~? diagnostic
 ";
     assert_eq!(expected, comply(original));
 }
diff --git a/src/doc/rustc-dev-guide/src/tests/ui.md b/src/doc/rustc-dev-guide/src/tests/ui.md
index 0b5a5b3ccbab..7332d1fb3851 100644
--- a/src/doc/rustc-dev-guide/src/tests/ui.md
+++ b/src/doc/rustc-dev-guide/src/tests/ui.md
@@ -232,9 +232,8 @@ The space character between `//~` (or other variants) and the subsequent text is
 negligible (i.e. there is no semantic difference between `//~ ERROR` and
 `//~ERROR` although the former is more common in the codebase).
 
-`~?
-<diagnostic kind>` (example being `~?
-ERROR`) is used to match diagnostics _without_ line info at all,
+`~? <diagnostic kind>` (example being `~? ERROR`)
+is used to match diagnostics _without_ line info at all,
 or where the line info is outside the main test file[^main test file].
 These annotations can be placed on any line in the test file.