diff --git a/debug/vasprintf_chk.c b/debug/vasprintf_chk.c
index 41c15689ee..f86320cadb 100644
--- a/debug/vasprintf_chk.c
+++ b/debug/vasprintf_chk.c
@@ -35,3 +35,4 @@ __vasprintf_chk (char **result_ptr, int flag, const char *format, va_list ap)
 
   return __vasprintf_internal (result_ptr, format, ap, mode);
 }
+libc_hidden_def (__vasprintf_chk)
diff --git a/debug/vfprintf_chk.c b/debug/vfprintf_chk.c
index 74b7c86add..999b6aa393 100644
--- a/debug/vfprintf_chk.c
+++ b/debug/vfprintf_chk.c
@@ -29,3 +29,4 @@ ___vfprintf_chk (FILE *fp, int flag, const char *format, va_list ap)
   return __vfprintf_internal (fp, format, ap, mode);
 }
 ldbl_strong_alias (___vfprintf_chk, __vfprintf_chk)
+ldbl_hidden_def (___vfprintf_chk, __vfprintf_chk)
diff --git a/elf/Makefile b/elf/Makefile
index 5d0c19a3e5..471dc0f8ba 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -1477,6 +1477,14 @@ rtld-stubbed-symbols = \
   realloc \
   # rtld-stubbed-symbols
 
+# These symbols might be emitted by the compiler when fortify is enabled
+# (through builtins).
+rtld-stubbed-symbols += \
+  __GI___vfprintf_chk \
+  __GI___vsprintf_chk \
+  __GI___vsyslog_chk \
+  # rtld-stubbed-symbols
+
 ifeq ($(have-ssp),yes)
 # rtld is not built with the stack protector, so these references will
 # go away in the rebuilds.
diff --git a/include/arpa/inet.h b/include/arpa/inet.h
index a02892f48a..6acb0dc83c 100644
--- a/include/arpa/inet.h
+++ b/include/arpa/inet.h
@@ -14,7 +14,6 @@ libc_hidden_proto (__inet_aton_exact)
 
 extern __typeof (inet_ntop) __inet_ntop;
 libc_hidden_proto (__inet_ntop)
-libc_hidden_proto (__inet_ntop_chk)
 
 libc_hidden_proto (inet_pton)
 extern __typeof (inet_pton) __inet_pton;
diff --git a/include/bits/inet-fortified-decl.h b/include/bits/inet-fortified-decl.h
index e6ad4d4663..c643425c25 100644
--- a/include/bits/inet-fortified-decl.h
+++ b/include/bits/inet-fortified-decl.h
@@ -1 +1,5 @@
 #include <inet/bits/inet-fortified-decl.h>
+
+#ifndef _ISOMAC
+libc_hidden_proto (__inet_ntop_chk)
+#endif
diff --git a/include/bits/stdio2-decl.h b/include/bits/stdio2-decl.h
index bbb052f192..9758bf4b55 100644
--- a/include/bits/stdio2-decl.h
+++ b/include/bits/stdio2-decl.h
@@ -1 +1,8 @@
 #include <libio/bits/stdio2-decl.h>
+
+#ifndef _ISOMAC
+libc_hidden_proto (__fgets_unlocked_chk)
+libc_hidden_ldbl_proto (vfprintf)
+libc_hidden_ldbl_proto (__vasprintf_chk)
+libc_hidden_ldbl_proto (__vfprintf_chk)
+#endif
diff --git a/include/bits/string_fortified.h b/include/bits/string_fortified.h
index 88bf073c9c..0cf0e76db1 100644
--- a/include/bits/string_fortified.h
+++ b/include/bits/string_fortified.h
@@ -1 +1,16 @@
+#ifndef _ISOMAC
+# if IS_IN(libc) && defined SHARED
+/* Redirect calls from __builtin_stpcpy_chk to internal __stpcpy when building
+   with fortify enable.  */
+__asm__ ("stpcpy = __GI___stpcpy");
+# endif
+
+/* Add the internal aliass attribute to symbol before they first usage on the
+   fortify wrappers.  */
+libc_hidden_builtin_proto (memcpy)
+libc_hidden_builtin_proto (mempcpy)
+libc_hidden_builtin_proto (memmove)
+libc_hidden_builtin_proto (memset)
+#endif
+
 #include <string/bits/string_fortified.h>
diff --git a/include/bits/syslog-decl.h b/include/bits/syslog-decl.h
index 491a263777..762b289184 100644
--- a/include/bits/syslog-decl.h
+++ b/include/bits/syslog-decl.h
@@ -1 +1,5 @@
 #include <misc/bits/syslog-decl.h>
+
+#ifndef _ISOMAC
+libc_hidden_ldbl_proto (__vsyslog_chk)
+#endif
diff --git a/include/bits/unistd-decl.h b/include/bits/unistd-decl.h
index 7fcbd272ac..dd6af7e4c8 100644
--- a/include/bits/unistd-decl.h
+++ b/include/bits/unistd-decl.h
@@ -1 +1,7 @@
 #include <posix/bits/unistd-decl.h>
+
+#ifndef _ISOMAC
+libc_hidden_proto (__read_chk)
+libc_hidden_proto (__getdomainname_chk)
+libc_hidden_proto (__getlogin_r_chk)
+#endif
diff --git a/include/bits/wchar2-decl.h b/include/bits/wchar2-decl.h
index 00b1b93342..f3b8a8cf87 100644
--- a/include/bits/wchar2-decl.h
+++ b/include/bits/wchar2-decl.h
@@ -1 +1,6 @@
 #include <wcsmbs/bits/wchar2-decl.h>
+
+#ifndef _ISOMAC
+libc_hidden_builtin_proto (__wmemset_chk)
+libc_hidden_proto (__wcrtomb_chk)
+#endif
diff --git a/include/stdio.h b/include/stdio.h
index e48d709919..b6f7787b1c 100644
--- a/include/stdio.h
+++ b/include/stdio.h
@@ -23,8 +23,12 @@
     redirecting ldouble to _Float128 variants.  We can therefore safely
     directly alias them to their internal name.  */
 # if __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 1 && IS_IN (libc)
-#  define stdio_hidden_ldbl_proto(p, f) \
-  extern __typeof (p ## f) p ## f __asm (__ASMNAME ("___ieee128_" #f));
+#  ifdef SHARED
+#   define stdio_hidden_ldbl_proto(p, f) __LDBL_REDIR2_DECL (f)
+#  else
+#   define stdio_hidden_ldbl_proto(p, f) \
+  extern __typeof (p ## f) p ## f __asm (#p __ASMNAME (#f "ieee128"));
+#  endif
 # elif __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 1
 #  define stdio_hidden_ldbl_proto(p,f) __LDBL_REDIR1_DECL (p ## f, p ## f ## ieee128)
 # else
@@ -70,10 +74,12 @@ extern int __printf_chk (int, const char *, ...);
 extern int __fprintf_chk (FILE *, int, const char *, ...);
 extern int __vprintf_chk (int, const char *, __gnuc_va_list);
 extern int __vfprintf_chk (FILE *, int, const char *, __gnuc_va_list);
+stdio_hidden_ldbl_proto (__, vfprintf_chk)
 extern char *__fgets_unlocked_chk (char *buf, size_t size, int n, FILE *fp);
 extern char *__fgets_chk (char *buf, size_t size, int n, FILE *fp);
 extern int __asprintf_chk (char **, int, const char *, ...) __THROW;
 extern int __vasprintf_chk (char **, int, const char *, __gnuc_va_list) __THROW;
+stdio_hidden_ldbl_proto (__, vasprintf_chk)
 extern int __dprintf_chk (int, int, const char *, ...);
 extern int __vdprintf_chk (int, int, const char *, __gnuc_va_list);
 extern int __obstack_printf_chk (struct obstack *, int, const char *, ...)
diff --git a/include/unistd.h b/include/unistd.h
index e241603b81..b042a485f9 100644
--- a/include/unistd.h
+++ b/include/unistd.h
@@ -32,10 +32,6 @@ libc_hidden_proto (readlinkat)
 libc_hidden_proto (fsync)
 libc_hidden_proto (fdatasync)
 
-libc_hidden_proto (__read_chk)
-libc_hidden_proto (__getdomainname_chk)
-libc_hidden_proto (__getlogin_r_chk)
-
 /* Now define the internal interfaces.  */
 extern int __access (const char *__name, int __type);
 libc_hidden_proto (__access)
diff --git a/include/wchar.h b/include/wchar.h
index bf32625736..6abb0d2697 100644
--- a/include/wchar.h
+++ b/include/wchar.h
@@ -166,7 +166,6 @@ libc_hidden_proto (putwc)
 
 libc_hidden_proto (mbrtowc)
 libc_hidden_proto (wcrtomb)
-libc_hidden_proto (__wcrtomb_chk)
 
 extern int __wcscmp (const wchar_t *__s1, const wchar_t *__s2)
      __THROW __attribute_pure__;
diff --git a/libio/Makefile b/libio/Makefile
index e143ccdb2c..3d42b3380d 100644
--- a/libio/Makefile
+++ b/libio/Makefile
@@ -60,6 +60,7 @@ routines_no_fortify += \
   iofgets_u \
   iofgetws \
   iofgetws_u \
+  iovdprintf \
   swprintf \
   vasprintf \
   vsnprintf \
diff --git a/misc/syslog.c b/misc/syslog.c
index 4186292b24..9578dd7307 100644
--- a/misc/syslog.c
+++ b/misc/syslog.c
@@ -115,10 +115,12 @@ ldbl_hidden_def (___syslog_chk, __syslog_chk)
 ldbl_strong_alias (___syslog_chk, __syslog_chk)
 
 void
-__vsyslog_chk (int pri, int flag, const char *fmt, va_list ap)
+___vsyslog_chk (int pri, int flag, const char *fmt, va_list ap)
 {
   __vsyslog_internal (pri, fmt, ap, (flag > 0) ? PRINTF_FORTIFY : 0);
 }
+ldbl_hidden_def (___vsyslog_chk, __vsyslog_chk)
+ldbl_strong_alias (___vsyslog_chk, __vsyslog_chk)
 
 void
 __vsyslog_internal (int pri, const char *fmt, va_list ap,
diff --git a/string/Makefile b/string/Makefile
index 7bc5affc56..dd95e1fedd 100644
--- a/string/Makefile
+++ b/string/Makefile
@@ -120,6 +120,7 @@ routines := \
 
 # Exclude fortified routines from being built with _FORTIFY_SOURCE
 routines_no_fortify += \
+  bzero \
   explicit_bzero \
   memcpy \
   memmove \
diff --git a/sysdeps/generic/symbol-hacks.h b/sysdeps/generic/symbol-hacks.h
index 1115e4c0a7..58398d33a5 100644
--- a/sysdeps/generic/symbol-hacks.h
+++ b/sysdeps/generic/symbol-hacks.h
@@ -6,6 +6,21 @@ asm ("memmove = __GI_memmove");
 asm ("memset = __GI_memset");
 asm ("memcpy = __GI_memcpy");
 
+/* clang might generate the internal fortfify calls when it is enabled,
+   through the buitintin.  */
+asm ("__vfprintf_chk = __GI___vfprintf_chk");
+asm ("__vsprintf_chk = __GI___vsprintf_chk");
+asm ("__vsyslog_chk = __GI___vsyslog_chk");
+asm ("__memcpy_chk = __GI___memcpy_chk");
+asm ("__memmove_chk = __GI___memmove_chk");
+asm ("__memset_chk = __GI___memset_chk");
+asm ("__mempcpy_chk = __GI___mempcpy_chk");
+asm ("__stpcpy_chk = __GI___stpcpy_chk");
+asm ("__strcpy_chk = __GI___strcpy_chk");
+asm ("strcpy = __GI_strcpy");
+asm ("strncpy = __GI_strncpy");
+asm ("strcat = __GI_strcat");
+
 /* Some targets do not use __stack_chk_fail_local.  In libc.so,
    redirect __stack_chk_fail to a hidden reference
    __stack_chk_fail_local, to avoid the PLT reference.
diff --git a/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-snprintf.c b/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-snprintf.c
index d458da7903..f880a55e0b 100644
--- a/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-snprintf.c
+++ b/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-snprintf.c
@@ -33,3 +33,7 @@ ___ieee128_snprintf (char *s, size_t maxlen, const char *format, ...)
   return done;
 }
 strong_alias (___ieee128_snprintf, __snprintfieee128)
+ldbl_hidden_def (___ieee128_snprintf, ___ieee128_snprintf)
+#ifdef SHARED
+strong_alias (___ieee128_snprintf, __GI____ieee128___snprintf)
+#endif
diff --git a/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-syslog.c b/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-syslog.c
index 197b149d0f..e08ae3aa28 100644
--- a/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-syslog.c
+++ b/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-syslog.c
@@ -56,7 +56,7 @@ hidden_def (___ieee128___syslog_chk)
 strong_alias (___ieee128___syslog_chk, __syslog_chkieee128)
 
 void
-___ieee128___vsyslog_chk (int pri, int flag, const char *fmt, va_list ap)
+____ieee128___vsyslog_chk (int pri, int flag, const char *fmt, va_list ap)
 {
   unsigned int mode = PRINTF_LDBL_USES_FLOAT128;
   if (flag > 0)
@@ -64,4 +64,5 @@ ___ieee128___vsyslog_chk (int pri, int flag, const char *fmt, va_list ap)
 
   __vsyslog_internal (pri, fmt, ap, mode);
 }
-strong_alias (___ieee128___vsyslog_chk, __vsyslog_chkieee128)
+strong_alias (____ieee128___vsyslog_chk, ___ieee128___vsyslog_chk)
+strong_alias (____ieee128___vsyslog_chk, __vsyslog_chkieee128)