Index: sbin/newfs/newfs.8
===================================================================
--- sbin/newfs/newfs.8
+++ sbin/newfs/newfs.8
@@ -89,7 +89,7 @@
 for details.
 .It Fl L Ar volname
 Add a volume label to the new file system.
-Legal characters are alphanumerics and underscores.
+Legal characters are alphanumerics, dashes and underscores.
 .It Fl N
 Cause the file system parameters to be printed out
 without really creating the file system.
Index: sbin/newfs/newfs.c
===================================================================
--- sbin/newfs/newfs.c
+++ sbin/newfs/newfs.c
@@ -153,10 +153,10 @@
 			volumelabel = optarg;
 			i = -1;
 			while (isalnum(volumelabel[++i]) ||
-			    volumelabel[i] == '_');
+			    volumelabel[i] == '_' || volumelabel[i] == '-');
 			if (volumelabel[i] != '\0') {
 				errx(1, "bad volume label. Valid characters "
-				    "are alphanumerics and underscores.");
+				    "are alphanumerics, dashes, and underscores.");
 			}
 			if (strlen(volumelabel) >= MAXVOLLEN) {
 				errx(1, "bad volume label. Length is longer than %d.",
Index: sbin/tunefs/tunefs.8
===================================================================
--- sbin/tunefs/tunefs.8
+++ sbin/tunefs/tunefs.8
@@ -112,7 +112,7 @@
 sets it to half of the space reserved to minfree.
 .It Fl L Ar volname
 Add/modify an optional file system volume label.
-Legal characters are alphanumerics and underscores.
+Legal characters are alphanumerics, dashes and underscores.
 .It Fl l Cm enable | disable
 Turn on/off MAC multilabel flag.
 .It Fl m Ar minfree
Index: sbin/tunefs/tunefs.c
===================================================================
--- sbin/tunefs/tunefs.c
+++ sbin/tunefs/tunefs.c
@@ -189,10 +189,13 @@
 			name = "volume label";
 			Lvalue = optarg;
 			i = -1;
-			while (isalnum(Lvalue[++i]) || Lvalue[i] == '_');
+			while (isalnum(Lvalue[++i]) || Lvalue[i] == '_' ||
+			    Lvalue[i] == '-')
+				;
 			if (Lvalue[i] != '\0') {
 				errx(10, "bad %s. Valid characters are "
-				    "alphanumerics and underscores.", name);
+				    "alphanumerics, dashes, and underscores.",
+				    name);
 			}
 			if (strlen(Lvalue) >= MAXVOLLEN) {
 				errx(10, "bad %s. Length is longer than %d.",