diff --git a/lib/msun/src/s_round.c b/lib/msun/src/s_round.c
index c3c0665d318..34b26f08c04 100644
--- a/lib/msun/src/s_round.c
+++ b/lib/msun/src/s_round.c
@@ -34,7 +34,7 @@ round(double x)
 {
 	double t;
 
-	if (!isnormal(x))
+	if (!isfinite(x))
 		return (x);
 
 	if (x >= 0.0) {
diff --git a/lib/msun/src/s_roundf.c b/lib/msun/src/s_roundf.c
index ba42e8e64a0..a7a3da93bc6 100644
--- a/lib/msun/src/s_roundf.c
+++ b/lib/msun/src/s_roundf.c
@@ -34,7 +34,7 @@ roundf(float x)
 {
 	float t;
 
-	if (!isnormal(x))
+	if (!isfinite(x))
 		return (x);
 
 	if (x >= 0.0) {