diff --git a/usr.bin/indent/indent.c b/usr.bin/indent/indent.c
index 02d34445ee75..08977bdd23cc 100644
--- a/usr.bin/indent/indent.c
+++ b/usr.bin/indent/indent.c
@@ -189,7 +189,7 @@ main(argc, argv)
 		in_name = argv[i];	/* remember name of input file */
 		input = fopen(in_name, "r");
 		if (input == 0)		/* check for open error */
-			err(1, in_name);
+			err(1, "%s", in_name);
 		continue;
 	    }
 	    else if (output == 0) {	/* we have the output file */
@@ -200,7 +200,7 @@ main(argc, argv)
 		}
 		output = fopen(out_name, "w");
 		if (output == 0)	/* check for create error */
-			err(1, out_name);
+			err(1, "%s", out_name);
 		continue;
 	    }
 	    errx(1, "unknown parameter: %s", argv[i]);
@@ -1160,23 +1160,23 @@ bakcopy()
     /* copy in_name to backup file */
     bakchn = creat(bakfile, 0600);
     if (bakchn < 0)
-	err(1, bakfile);
+	err(1, "%s", bakfile);
     while (n = read(fileno(input), buff, sizeof buff))
 	if (write(bakchn, buff, n) != n)
-	    err(1, bakfile);
+	    err(1, "%s", bakfile);
     if (n < 0)
-	err(1, in_name);
+	err(1, "%s", in_name);
     close(bakchn);
     fclose(input);
 
     /* re-open backup file as the input file */
     input = fopen(bakfile, "r");
     if (input == 0)
-	err(1, bakfile);
+	err(1, "%s", bakfile);
     /* now the original input file will be the output */
     output = fopen(in_name, "w");
     if (output == 0) {
 	unlink(bakfile);
-	err(1, in_name);
+	err(1, "%s", in_name);
     }
 }
diff --git a/usr.bin/ktrace/ktrace.c b/usr.bin/ktrace/ktrace.c
index 1c5a98ba6796..48d4871a210b 100644
--- a/usr.bin/ktrace/ktrace.c
+++ b/usr.bin/ktrace/ktrace.c
@@ -136,14 +136,14 @@ main(argc, argv)
 			ops |= pid ? KTROP_CLEAR : KTROP_CLEARFILE;
 
 		if (ktrace(tracefile, ops, trpoints, pid) < 0)
-			err(1, tracefile);
+			err(1, "%s", tracefile);
 		exit(0);
 	}
 
 	omask = umask(S_IRWXG|S_IRWXO);
 	if (append) {
 		if ((fd = open(tracefile, O_CREAT | O_WRONLY, DEFFILEMODE)) < 0)
-			err(1, tracefile);
+			err(1, "%s", tracefile);
 		if (fstat(fd, &sb) != 0 || sb.st_uid != getuid())
 			errx(1, "Refuse to append to %s not owned by you.",
 			    tracefile);
@@ -152,19 +152,19 @@ main(argc, argv)
 			err(1, "unlink %s", tracefile);
 		if ((fd = open(tracefile, O_CREAT | O_EXCL | O_WRONLY,
 		    DEFFILEMODE)) < 0)
-			err(1, tracefile);
+			err(1, "%s", tracefile);
 	}
 	(void)umask(omask);
 	(void)close(fd);
 
 	if (*argv) { 
 		if (ktrace(tracefile, ops, trpoints, getpid()) < 0)
-			err(1, tracefile);
+			err(1, "%s", tracefile);
 		execvp(argv[0], &argv[0]);
 		err(1, "exec of '%s' failed", argv[0]);
 	}
 	else if (ktrace(tracefile, ops, trpoints, pid) < 0)
-		err(1, tracefile);
+		err(1, "%s", tracefile);
 	exit(0);
 }
 
diff --git a/usr.bin/kzip/kzip.c b/usr.bin/kzip/kzip.c
index 97e1a4db356d..5af945a991ca 100644
--- a/usr.bin/kzip/kzip.c
+++ b/usr.bin/kzip/kzip.c
@@ -85,13 +85,13 @@ main(int argc, char **argv)
 
 	fdi = open(kernname ,O_RDONLY);
 	if(fdi<0) {
-		warn(kernname);
+		warn("%s", kernname);
 		return 2;
 	}
 
 	/* figure out how big the uncompressed image will be */
 	if (read (fdi, (char *)&hdr, sizeof(hdr)) != sizeof(hdr))
-		err(2, argv[1]);
+		err(2, "%s", argv[1]);
 
 	size = hdr.a_text + hdr.a_data + hdr.a_bss;
 	entry = hdr.a_entry & 0x00FFFFFF;
@@ -106,7 +106,7 @@ main(int argc, char **argv)
 
 	fdo = open(obj,O_WRONLY|O_TRUNC|O_CREAT,0666);
 	if(fdo<0) {
-		warn(obj);
+		warn("%s", obj);
 		return 2;
 	}
 
@@ -222,13 +222,13 @@ main(int argc, char **argv)
 
 		fdn = open(obj ,O_RDONLY);
 		if(fdn<0) {
-			warn(obj);
+			warn("%s", obj);
 			return 3;
 		}
 
 		/* figure out how big the compressed image is */
 		if (read (fdn, (char *)&hdr, sizeof(hdr)) != sizeof(hdr)) {
-			warn(obj);
+			warn("%s", obj);
 			return 3;
 		}
 		close(fdn);
@@ -251,11 +251,11 @@ extract (char *file)
 	struct exec hdr;
 
 	if (read (0, (char *)&hdr, sizeof(hdr)) != sizeof(hdr))
-		err(2, file);
+		err(2, "%s", file);
 	if (hdr.a_magic != ZMAGIC)
 		errx(2, "bad magic in file %s, probably not a kernel", file);
 	if (lseek (0, N_TXTOFF(hdr), 0) < 0)
-		err(2, file);
+		err(2, "%s", file);
 
 	sz = N_SYMOFF (hdr) - N_TXTOFF (hdr);
 
@@ -269,7 +269,7 @@ extract (char *file)
 		n = read (0, buf, l);
 		if (n != l) {
 			if (n == -1)
-				err(1, file);
+				err(1, "%s", file);
 			else
 				errx(1, "unexpected EOF");
 		}
diff --git a/usr.bin/lam/lam.c b/usr.bin/lam/lam.c
index 277081095af7..e65df368ce8d 100644
--- a/usr.bin/lam/lam.c
+++ b/usr.bin/lam/lam.c
@@ -118,7 +118,7 @@ getargs(av)
 			if (*p == '-')
 				ip->fp = stdin;
 			else if ((ip->fp = fopen(p, "r")) == NULL) {
-				err(1, p);
+				err(1, "%s", p);
 			}
 			ip->pad = P;
 			if (!ip->sepstring)