diff --git a/include/pybind11/detail/descr.h b/include/pybind11/detail/descr.h
index 6418aa8979..be0eb078c8 100644
--- a/include/pybind11/detail/descr.h
+++ b/include/pybind11/detail/descr.h
@@ -138,7 +138,7 @@ constexpr enable_if_t<!B, T2> _(const T1 &d1, const T2 &d2) {
     return const_name<B, T1, T2>(d1, d2);
 }
 
-#if defined(PYBIND11_CPP17)
+#    if defined(PYBIND11_CPP17)
 
 template <auto Bool,
           typename std::enable_if<std::is_same<decltype(Bool), bool>::value, int>::type = 0>
@@ -148,9 +148,9 @@ auto constexpr _() {
 
 template <auto Size,
           typename std::enable_if<!std::is_same<decltype(Size), bool>::value, int>::type = 0>
-#else
+#    else
 template <size_t Size>
-#endif
+#    endif
 auto constexpr _() -> remove_cv_t<decltype(int_to_str<Size / 10, Size % 10>::digits)> {
     return const_name<Size>();
 }