diff --git a/include/bitop.h b/include/bitop.h
index e5d2310af..a845761e1 100644
--- a/include/bitop.h
+++ b/include/bitop.h
@@ -297,6 +297,7 @@ template <typename T=unsigned int> static inline constexpr bool ispowerof2(const
  *
  * The constexpr templated version will trigger a static_assert if v == 0.
  *
+ * log2(2^32 - 1) == 31                         2^32 - 1 = 0xFFFFFFFF
  * log2(2^31) == 31
  * log2(2^30) == 30
  * log2(2^16) == 16                             2^16 == 65536