diff --git a/libcxx/include/__bit/countr.h b/libcxx/include/__bit/countr.h
index a01ec96417f08..4ccfc81605638 100644
--- a/libcxx/include/__bit/countr.h
+++ b/libcxx/include/__bit/countr.h
@@ -45,7 +45,7 @@ _LIBCPP_NODISCARD _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 int __coun
   if (__t == 0)
     return numeric_limits<_Tp>::digits;
 
-  return __builtin_ctz(__t);
+  return __builtin_ctzg(__t);
 }
 
 #else // __has_builtin(__builtin_ctzg)
diff --git a/libcxx/src/include/ryu/ryu.h b/libcxx/src/include/ryu/ryu.h
index de1744ba20a0e..7b19ecfec5915 100644
--- a/libcxx/src/include/ryu/ryu.h
+++ b/libcxx/src/include/ryu/ryu.h
@@ -43,7 +43,6 @@
 // Avoid formatting to keep the changes with the original code minimal.
 // clang-format off
 
-#include <__bit/countr.h>
 #include <__charconv/chars_format.h>
 #include <__charconv/to_chars_result.h>
 #include <__config>