diff -Nru /n/sources/plan9/sys/src/libc/9sys/getnetconninfo.c /sys/src/libc/9sys/getnetconninfo.c
--- /n/sources/plan9/sys/src/libc/9sys/getnetconninfo.c	Fri Feb 11 21:39:34 2005
+++ /sys/src/libc/9sys/getnetconninfo.c	Tue Dec 15 00:00:00 2015
@@ -77,7 +77,7 @@
 	/* figure out bind spec */
 	d = dirstat(nci->dir);
 	if(d != nil){
-		sprint(spec, "#%C%d", d->type, d->dev);
+		snprint(spec, sizeof spec, "#%C%d", d->type, d->dev);
 		nci->spec = strdup(spec);
 	}
 	if(nci->spec == nil)
diff -Nru /n/sources/plan9/sys/src/libc/9sys/postnote.c /sys/src/libc/9sys/postnote.c
--- /n/sources/plan9/sys/src/libc/9sys/postnote.c	Sun Dec 12 01:21:52 1999
+++ /sys/src/libc/9sys/postnote.c	Tue Dec 15 00:00:00 2015
@@ -9,10 +9,10 @@
 
 	switch(group) {
 	case PNPROC:
-		sprint(file, "/proc/%d/note", pid);
+		snprint(file, sizeof file, "/proc/%d/note", pid);
 		break;
 	case PNGROUP:
-		sprint(file, "/proc/%d/notepg", pid);
+		snprint(file, sizeof file, "/proc/%d/notepg", pid);
 		break;
 	default:
 		return -1;
diff -Nru /n/sources/plan9/sys/src/libc/9sys/pushssl.c /sys/src/libc/9sys/pushssl.c
--- /n/sources/plan9/sys/src/libc/9sys/pushssl.c	Thu Feb 28 20:15:38 2002
+++ /sys/src/libc/9sys/pushssl.c	Tue Dec 15 00:00:00 2015
@@ -21,7 +21,7 @@
 	if(n < 0)
 		goto error;
 	buf[n] = 0;
-	sprint(dname, "#D/ssl/%s/data", buf);
+	snprint(dname, sizeof dname, "#D/ssl/%s/data", buf);
 	data = open(dname, ORDWR);
 	if(data < 0)
 		goto error;
diff -Nru /n/sources/plan9/sys/src/libc/9sys/pushtls.c /sys/src/libc/9sys/pushtls.c
--- /n/sources/plan9/sys/src/libc/9sys/pushtls.c	Thu Mar 28 20:26:37 2013
+++ /sys/src/libc/9sys/pushtls.c	Tue Dec 15 00:00:00 2015
@@ -60,13 +60,13 @@
 		sprint(dir, "#a/tls/%s", buf);
 
 	// get application fd
-	sprint(dname, "#a/tls/%s/data", buf);
+	snprint(dname, sizeof dname, "#a/tls/%s/data", buf);
 	data = open(dname, ORDWR);
 	if(data < 0)
 		goto error;
 
 	// get handshake fd
-	sprint(dname, "#a/tls/%s/hand", buf);
+	snprint(dname, sizeof dname, "#a/tls/%s/hand", buf);
 	hand = open(dname, ORDWR);
 	if(hand < 0)
 		goto error;
diff -Nru /n/sources/plan9/sys/src/libc/fmt/fltfmt.c /sys/src/libc/fmt/fltfmt.c
--- /n/sources/plan9/sys/src/libc/fmt/fltfmt.c	Thu Oct 27 00:52:32 2005
+++ /sys/src/libc/fmt/fltfmt.c	Sun Nov  6 00:00:00 2016
@@ -133,13 +133,13 @@
 		d = e;
 		s1[NSIGNIF-2] = '0';
 		s1[NSIGNIF-1] = '0';
-		sprint(s1+NSIGNIF, "e%d", e-NSIGNIF+1);
+		snprint(s1+NSIGNIF, sizeof s1-NSIGNIF, "e%d", e-NSIGNIF+1);
 		g = strtod(s1, nil);
 		if(g == f)
 			goto found;
 		if(xadd(s1, NSIGNIF-3, 1)) {
 			e++;
-			sprint(s1+NSIGNIF, "e%d", e-NSIGNIF+1);
+			snprint(s1+NSIGNIF, sizeof s1-NSIGNIF, "e%d", e-NSIGNIF+1);
 		}
 		g = strtod(s1, nil);
 		if(g == f)
@@ -152,7 +152,7 @@
 	 * convert back so s1 gets exact answer
 	 */
 	for(;;) {
-		sprint(s1+NSIGNIF, "e%d", e-NSIGNIF+1);
+		snprint(s1+NSIGNIF, sizeof s1-NSIGNIF, "e%d", e-NSIGNIF+1);
 		g = strtod(s1, nil);
 		if(f > g) {
 			if(xadd(s1, NSIGNIF-1, 1))