diff --git a/ChangeLog b/ChangeLog
index f72f22e2df..2d88f74d6b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2016-06-09  Joseph Myers  <joseph@codesourcery.com>
+
+	[BZ #20232]
+	* sysdeps/ieee754/ldbl-128/s_expm1l.c (__expm1l): Add NaN input to
+	itself.
+
 2016-06-09  H.J. Lu  <hongjiu.lu@intel.com>
 
 	* sysdeps/x86_64/start.S (_start): Always indirect branch to
diff --git a/sysdeps/ieee754/ldbl-128/s_expm1l.c b/sysdeps/ieee754/ldbl-128/s_expm1l.c
index b1100a9d0e..da902efafd 100644
--- a/sysdeps/ieee754/ldbl-128/s_expm1l.c
+++ b/sysdeps/ieee754/ldbl-128/s_expm1l.c
@@ -111,8 +111,8 @@ __expm1l (long double x)
       /* Infinity (which must be negative infinity). */
       if (((ix & 0xffff) | u.parts32.w1 | u.parts32.w2 | u.parts32.w3) == 0)
 	return -1.0L;
-      /* NaN. No invalid exception. */
-      return x;
+      /* NaN.  Invalid exception if signaling.  */
+      return x + x;
     }
 
   /* expm1(+- 0) = +- 0.  */