diff --git a/src/fallback.cpp b/src/fallback.cpp
index a0db093a9..bcfc4d926 100644
--- a/src/fallback.cpp
+++ b/src/fallback.cpp
@@ -394,13 +394,13 @@ int flock(int fd, int op) {
 // For platforms without wcstod_l C extension, wrap wcstod after changing the
 // thread-specific locale.
 double fish_compat::wcstod_l(const wchar_t *enptr, wchar_t **endptr, locale_t loc) {
-    char *saved_locale = strdup(setlocale(LC_NUMERIC, NULL));
-    // Yes, this is hardcoded to use the "C" locale.
-    // That's the only thing we need, and uselocale(loc) broke in my testing.
-    setlocale(LC_NUMERIC, "C");
+    // Create and use a new, thread-specific locale
+    locale_t locale = newlocale(LC_NUMERIC, "C", nullptr);
+    locale_t prev_locale = uselocale(locale);
     double ret = wcstod(enptr, endptr);
-    setlocale(LC_NUMERIC, saved_locale);
-    free(saved_locale);
+    // Restore the old locale before freeing the locale we created and are still using
+    uselocale(prev_locale);
+    freelocale(locale);
     return ret;
 }
 #endif // defined(wcstod_l)