diff --git a/ChangeLog b/ChangeLog
index c6216c982b..72605d4631 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,14 @@
+2015-09-18  Wilco Dijkstra  <wdijkstr@arm.com>
+
+	* sysdeps/ieee754/dbl-64/s_signbit.c (__signbit):
+	Use __builtin_signbit.
+	* sysdeps/ieee754/flt-32/s_signbitf.c (__signbitf):
+	Use __builtin_signbitf.
+	* sysdeps/ieee754/ldbl-128/s_signbitl.c (__signbitl):
+	Use __builtin_signbitl.
+	* sysdeps/ieee754/ldbl-128ibm/s_signbitl.c (___signbitl): Likewise.
+	* sysdeps/ieee754/ldbl-96/s_signbitl.c (__signbitl): Likewise.
+
 2015-09-18  Wilco Dijkstra  <wdijkstr@arm.com>
 
 	[BZ #15367]
diff --git a/sysdeps/ieee754/dbl-64/s_signbit.c b/sysdeps/ieee754/dbl-64/s_signbit.c
index 764f11a2d2..91797eecdd 100644
--- a/sysdeps/ieee754/dbl-64/s_signbit.c
+++ b/sysdeps/ieee754/dbl-64/s_signbit.c
@@ -19,13 +19,8 @@
 
 #include <math.h>
 
-#include <math_private.h>
-
 int
 __signbit (double x)
 {
-  int32_t hx;
-
-  GET_HIGH_WORD (hx, x);
-  return hx & 0x80000000;
+  return __builtin_signbit (x);
 }
diff --git a/sysdeps/ieee754/flt-32/s_signbitf.c b/sysdeps/ieee754/flt-32/s_signbitf.c
index 169820e9df..034c17529c 100644
--- a/sysdeps/ieee754/flt-32/s_signbitf.c
+++ b/sysdeps/ieee754/flt-32/s_signbitf.c
@@ -19,13 +19,8 @@
 
 #include <math.h>
 
-#include <math_private.h>
-
 int
 __signbitf (float x)
 {
-  int32_t hx;
-
-  GET_FLOAT_WORD (hx, x);
-  return hx & 0x80000000;
+  return __builtin_signbitf (x);
 }
diff --git a/sysdeps/ieee754/ldbl-128/s_signbitl.c b/sysdeps/ieee754/ldbl-128/s_signbitl.c
index acfe859a2e..ea689a6fe5 100644
--- a/sysdeps/ieee754/ldbl-128/s_signbitl.c
+++ b/sysdeps/ieee754/ldbl-128/s_signbitl.c
@@ -19,13 +19,8 @@
 
 #include <math.h>
 
-#include <math_private.h>
-
 int
 __signbitl (long double x)
 {
-  int64_t e;
-
-  GET_LDOUBLE_MSW64 (e, x);
-  return e < 0;
+  return __builtin_signbitl (x);
 }
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_signbitl.c b/sysdeps/ieee754/ldbl-128ibm/s_signbitl.c
index e95ad55e32..5e2bd90704 100644
--- a/sysdeps/ieee754/ldbl-128ibm/s_signbitl.c
+++ b/sysdeps/ieee754/ldbl-128ibm/s_signbitl.c
@@ -18,18 +18,12 @@
    <http://www.gnu.org/licenses/>.  */
 
 #include <math.h>
-#include <math_private.h>
 #include <math_ldbl_opt.h>
 
 int
 ___signbitl (long double x)
 {
-  int64_t e;
-  double xhi;
-
-  xhi = ldbl_high (x);
-  EXTRACT_WORDS64 (e, xhi);
-  return e < 0;
+  return __builtin_signbitl (x);
 }
 #if IS_IN (libm)
 long_double_symbol (libm, ___signbitl, __signbitl);
diff --git a/sysdeps/ieee754/ldbl-96/s_signbitl.c b/sysdeps/ieee754/ldbl-96/s_signbitl.c
index bbe72a62ea..ea689a6fe5 100644
--- a/sysdeps/ieee754/ldbl-96/s_signbitl.c
+++ b/sysdeps/ieee754/ldbl-96/s_signbitl.c
@@ -19,13 +19,8 @@
 
 #include <math.h>
 
-#include <math_private.h>
-
 int
 __signbitl (long double x)
 {
-  int32_t e;
-
-  GET_LDOUBLE_EXP (e, x);
-  return e & 0x8000;
+  return __builtin_signbitl (x);
 }