diff --git a/skeletons/REAL.c b/skeletons/REAL.c
index 6d3e55e..d395c84 100644
--- a/skeletons/REAL.c
+++ b/skeletons/REAL.c
@@ -57,7 +57,7 @@
 		buf = "<NOT-A-NUMBER/>";
 		buflen = 15;
 		return (cb(buf, buflen, app_key) < 0) ? -1 : buflen;
-	} else if(isinf(d)) {
+	} else if(!finite(d)) {
 		if(copysign(1.0, d) < 0.0) {
 			buf = "<MINUS-INFINITY/>";
 			buflen = 17;
@@ -416,7 +416,7 @@
 			st->buf[0] = 0x42;	/* NaN */
 			st->buf[1] = 0;
 			st->size = 1;
-		} else if(isinf(dbl_value)) {
+		} else if(!finite(dbl_value)) {
 			if(copysign(1.0, dbl_value) < 0.0) {
 				st->buf[0] = 0x41;	/* MINUS-INFINITY */
 			} else {