diff --git a/ChangeLog b/ChangeLog
index 0126fb391b..9c6a1b97bd 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2018-05-24  Gabriel F. T. Gomes  <gabriel@inconstante.eti.br>
+
+	[BZ #23171]
+	* math/math.h [C++] (iseqsig): Fix parameter type for the long
+	double version.
+
 2018-06-01  Florian Weimer  <fweimer@redhat.com>
 
 	[BZ #23236]
diff --git a/NEWS b/NEWS
index b8bd101f6c..c323323259 100644
--- a/NEWS
+++ b/NEWS
@@ -139,6 +139,7 @@ The following bugs are resolved with this release:
   [23024] getlogin_r: return early when linux sentinel value is set
   [23037] resolv: Fully initialize struct mmsghdr in send_dg
   [23137] s390: Fix blocking pthread_join
+  [23171] Fix parameter type in C++ version of iseqsig
   [23196] __mempcpy_avx512_no_vzeroupper mishandles large copies
   [23236] Harden function pointers in _IO_str_fields
 
diff --git a/math/math.h b/math/math.h
index 5a282b8c6b..4c30306d58 100644
--- a/math/math.h
+++ b/math/math.h
@@ -880,7 +880,7 @@ template<> struct __iseqsig_type<double>
 
 template<> struct __iseqsig_type<long double>
 {
-  static int __call (double __x, double __y) throw ()
+  static int __call (long double __x, long double __y) throw ()
   {
 #  ifndef __NO_LONG_DOUBLE_MATH
     return __iseqsigl (__x, __y);