diff --git a/ChangeLog b/ChangeLog
index b191c408a4..5132b96807 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2015-08-26  Stan Shebs  <stanshebs@google.com>
+
+	* sysdeps/ieee754/ldbl-96/k_tanl.c: Include <libc-internal.h>.
+	(__kernel_tanl): Ignore uninitialized warnings around use of SIGN.
+
 2015-08-26  Carlos Eduardo Seo  <cseo@linux.vnet.ibm.com>
 
 	* sysdeps/powerpc/bits/hwcap.h: Add PPC_FEATURE2_HTM_NOSC.
diff --git a/sysdeps/ieee754/ldbl-96/k_tanl.c b/sysdeps/ieee754/ldbl-96/k_tanl.c
index ae6821d984..6276c06e71 100644
--- a/sysdeps/ieee754/ldbl-96/k_tanl.c
+++ b/sysdeps/ieee754/ldbl-96/k_tanl.c
@@ -57,6 +57,7 @@
  */
 
 #include <float.h>
+#include <libc-internal.h>
 #include <math.h>
 #include <math_private.h>
 static const long double
@@ -136,8 +137,19 @@ __kernel_tanl (long double x, long double y, int iy)
     {
       v = (long double) iy;
       w = (v - 2.0 * (x - (w * w / (w + v) - r)));
+      /* SIGN is set for arguments that reach this code, but not
+        otherwise, resulting in warnings that it may be used
+        uninitialized although in the cases where it is used it has
+        always been set.  */
+      DIAG_PUSH_NEEDS_COMMENT;
+#if __GNUC_PREREQ (4, 7)
+      DIAG_IGNORE_NEEDS_COMMENT (4.8, "-Wmaybe-uninitialized");
+#else
+      DIAG_IGNORE_NEEDS_COMMENT (4.8, "-Wuninitialized");
+#endif
       if (sign < 0)
 	w = -w;
+      DIAG_POP_NEEDS_COMMENT;
       return w;
     }
   if (iy == 1)