diff --git a/libquadmath/ChangeLog b/libquadmath/ChangeLog
index fe1dfed0daa..71fbc2f547b 100644
--- a/libquadmath/ChangeLog
+++ b/libquadmath/ChangeLog
@@ -1,3 +1,8 @@
+2011-02-20  Jakub Jelinek  <jakub@redhat.com>
+
+	PR bootstrap/47827
+	* printf/quadmath-printf.h (NAN): Redefine to __builtin_nanf ("").
+
 2011-02-17  Jakub Jelinek  <jakub@redhat.com>
 
 	* libquadmath.texi (FLT128_DIG, FLT128_MIN_10_EXP,
diff --git a/libquadmath/printf/quadmath-printf.h b/libquadmath/printf/quadmath-printf.h
index 9e574c1eccc..32ebcec928c 100644
--- a/libquadmath/printf/quadmath-printf.h
+++ b/libquadmath/printf/quadmath-printf.h
@@ -181,3 +181,6 @@ __quadmath_do_putc (struct __quadmath_printf_file *fp, int wide,
 
 #undef _itoa
 #define _itoa __quadmath_itoa
+
+#undef NAN
+#define NAN __builtin_nanf ("")