diff --git a/sim/rx/ChangeLog b/sim/rx/ChangeLog
index 7049d948b7a..104578cf361 100644
--- a/sim/rx/ChangeLog
+++ b/sim/rx/ChangeLog
@@ -1,3 +1,9 @@
+2016-04-27  Nick Clifton  <nickc@redhat.com>
+
+	PR target/20000
+	* fpu.c (check_exceptions): Fix typo checking for signalling
+	NANs.
+
 2016-01-10  Mike Frysinger  <vapier@gentoo.org>
 
 	* config.in, configure: Regenerate.
diff --git a/sim/rx/fpu.c b/sim/rx/fpu.c
index d3f4bdbf694..aa7fd2da051 100644
--- a/sim/rx/fpu.c
+++ b/sim/rx/fpu.c
@@ -433,7 +433,7 @@ check_exceptions (FP_Parts *a, FP_Parts *b, fp_t *c,
       FP_RAISE (V);
       if (a->type == FP_SNAN)
 	*c = a->orig_value | 0x00400000;
-      else if  (a->type == FP_SNAN)
+      else if  (b->type == FP_SNAN)
 	*c = b->orig_value | 0x00400000;
       else
 	*c = 0x7fc00000;