diff --git a/sim/mips/ChangeLog b/sim/mips/ChangeLog
index d963ab3fec..9b14b8f9e2 100644
--- a/sim/mips/ChangeLog
+++ b/sim/mips/ChangeLog
@@ -1,3 +1,7 @@
+2005-07-08  Ian Lance Taylor  <ian@airs.com>
+
+	* tconfig.in (SIM_QUIET_NAN_NEGATED): Define.
+
 2005-06-16  David Ung  <davidu@mips.com>
             Nigel Stephens  <nigel@mips.com>
 
diff --git a/sim/mips/tconfig.in b/sim/mips/tconfig.in
index 7cea8454fd..2f14ce1197 100644
--- a/sim/mips/tconfig.in
+++ b/sim/mips/tconfig.in
@@ -31,3 +31,6 @@ MODULE_INSTALL_FN dv_sockser_install;
 /* Define this if the target cpu is bi-endian
    and the simulator supports it.  */
 #define SIM_HAVE_BIENDIAN
+
+/* MIPS uses an unusual format for floating point quiet NaNs.  */
+#define SIM_QUIET_NAN_NEGATED