diff --git a/include/bh_python/register_axis.hpp b/include/bh_python/register_axis.hpp
index 3db77c2b..e01b5dcb 100644
--- a/include/bh_python/register_axis.hpp
+++ b/include/bh_python/register_axis.hpp
@@ -36,7 +36,7 @@ auto vectorize_index(T input) {
 }
 
 #ifdef __cpp_noexcept_function_type
-# define BHP_NOEXCEPT_17 noexcept
+#define BHP_NOEXCEPT_17 noexcept
 #else
 #define BHP_NOEXCEPT_17
 #endif