diff --git a/include/fast_float/ascii_number.h b/include/fast_float/ascii_number.h
index e1e5be6..d571fcb 100644
--- a/include/fast_float/ascii_number.h
+++ b/include/fast_float/ascii_number.h
@@ -10,8 +10,8 @@
 
 namespace fast_float {
 
-// Next function can be micro-optimized to (c & 0x30) == 0x30, but compilers are entirely
-// able to optimize c >= '0' && c <= '9' very well.
+// Next function can be micro-optimized, but compilers are entirely
+// able to optimize it well.
 fastfloat_really_inline bool is_integer(char c)  noexcept  { return c >= '0' && c <= '9'; }