diff --git a/build_tools/release-notes.sh b/build_tools/release-notes.sh
index ee4c8a673..05c99123c 100755
--- a/build_tools/release-notes.sh
+++ b/build_tools/release-notes.sh
@@ -62,7 +62,7 @@ previous_minor_version=${previous_version%.*}
 
     if [ "$minor_version" != "$previous_minor_version" ]; then {
         JoinEscaped() {
-            sed 's/\S/\\&/g' |
+            LC_CTYPE=C.UTF-8 sed 's/\S/\\&/g' |
                 awk '
                     NR != 1 { printf ",\n" }
                     { printf "%s", $0 }
diff --git a/tests/test_driver.py b/tests/test_driver.py
index c4b2bb1b5..a75dbd6f7 100755
--- a/tests/test_driver.py
+++ b/tests/test_driver.py
@@ -86,7 +86,6 @@ def makeenv(script_path: Path, home: Path) -> Dict[str, str]:
             "XDG_CACHE_HOME": str(xdg_cache),
             "fish_test_helper": str(home.parent / "fish_test_helper"),
             "LANG": "C",
-            "LC_CTYPE": "en_US.UTF-8",
         }
     )