diff --git a/man/mkfs.btrfs.8.in b/man/mkfs.btrfs.8.in
index 1e14c6c..f51291c 100644
--- a/man/mkfs.btrfs.8.in
+++ b/man/mkfs.btrfs.8.in
@@ -5,14 +5,14 @@ mkfs.btrfs \- create an btrfs filesystem
 .B mkfs.btrfs
 [ \fB\-A\fP\fI alloc-start\fP ]
 [ \fB\-b\fP\fI byte-count\fP ]
-[ \fB \-d\fP\fI data-profile\fP ]
-[ \fB \-l\fP\fI leafsize\fP ]
-[ \fB \-L\fP\fI label\fP ]
-[ \fB \-m\fP\fI metadata profile\fP ]
-[ \fB \-n\fP\fI nodesize\fP ]
-[ \fB \-s\fP\fI sectorsize\fP ]
-[ \fB \-h\fP ]
-[ \fB \-V\fP ] \fI device\fP [ \fI device ...\fP ]
+[ \fB\-d\fP\fI data-profile\fP ]
+[ \fB\-f\fP ]
+[ \fB\-l\fP\fI leafsize\fP ]
+[ \fB\-L\fP\fI label\fP ]
+[ \fB\-m\fP\fI metadata profile\fP ]
+[ \fB\-n\fP\fI nodesize\fP ]
+[ \fB\-s\fP\fI sectorsize\fP ]
+[ \fB\-V\fP ] \fIdevice\fP [ \fIdevice ...\fP ]
 .SH DESCRIPTION
 .B mkfs.btrfs
 is used to create an btrfs filesystem (usually in a disk partition, or an array
@@ -34,6 +34,9 @@ mkfs.btrfs uses all the available storage for the filesystem.
 Specify how the data must be spanned across the devices specified. Valid
 values are raid0, raid1, raid10 or single.
 .TP
+\fB\-f\fR, \fB\-\-force \fR
+Don't check if the device is already mounted.
+.TP
 \fB\-l\fR, \fB\-\-leafsize \fIsize\fR
 Specify the leaf size, the least data item in which btrfs stores data. The
 default value is the page size.
diff --git a/mkfs.c b/mkfs.c
index 2e99b95..21bcc7a 100644
--- a/mkfs.c
+++ b/mkfs.c
@@ -271,6 +271,7 @@ static void print_usage(void)
 	fprintf(stderr, "\t -A --alloc-start the offset to start the FS\n");
 	fprintf(stderr, "\t -b --byte-count total number of bytes in the FS\n");
 	fprintf(stderr, "\t -d --data data profile, raid0, raid1, raid10 or single\n");
+	fprintf(stderr, "\t -f --force don't check if a device is already mounted\n");
 	fprintf(stderr, "\t -l --leafsize size of btree leaves\n");
 	fprintf(stderr, "\t -L --label set a label\n");
 	fprintf(stderr, "\t -m --metadata metadata profile, values like data profile\n");
@@ -332,6 +333,7 @@ static struct option long_options[] = {
 	{ "sectorsize", 1, NULL, 's' },
 	{ "data", 1, NULL, 'd' },
 	{ "version", 0, NULL, 'V' },
+	{ "force", 0, NULL, 'f' },
 	{ 0, 0, 0, 0}
 };
 
@@ -358,10 +360,11 @@ int main(int ac, char **av)
 	int first_fd;
 	int ret;
 	int i;
+	int force=0;
 
 	while(1) {
 		int c;
-		c = getopt_long(ac, av, "A:b:l:n:s:m:d:L:V", long_options,
+		c = getopt_long(ac, av, "A:b:l:n:s:m:d:L:Vf", long_options,
 				&option_index);
 		if (c < 0)
 			break;
@@ -401,6 +404,9 @@ int main(int ac, char **av)
 			case 'V':
 				print_version();
 				break;
+			case 'f':
+				force=1;
+				break;
 			default:
 				print_usage();
 		}
@@ -423,13 +429,16 @@ int main(int ac, char **av)
 
 	file = av[optind++];
 	ret = check_mounted(file);
-	if (ret < 0) {
-		fprintf(stderr, "error checking %s mount status\n", file);
-		exit(1);
-	}
-	if (ret == 1) {
-		fprintf(stderr, "%s is mounted\n", file);
-		exit(1);
+	if(!force){
+		if (ret < 0) {
+			fprintf(stderr, "error checking %s mount status\n", 
+				file);
+			exit(1);
+		}
+		if (ret == 1) {	
+			fprintf(stderr, "%s is mounted\n", file);
+			exit(1);
+		}
 	}
 	ac--;
 	fd = open(file, O_RDWR);
@@ -479,15 +488,17 @@ int main(int ac, char **av)
 	zero_end = 1;
 	while(ac-- > 0) {
 		file = av[optind++];
-		ret = check_mounted(file);
-		if (ret < 0) {
-			fprintf(stderr, "error checking %s mount status\n",
-				file);
-			exit(1);
-		}
-		if (ret == 1) {
-			fprintf(stderr, "%s is mounted\n", file);
-			exit(1);
+		if(!force){
+			ret = check_mounted(file);
+			if (ret < 0) {
+				fprintf(stderr, "error checking %s"
+					" mount status\n",file);
+				exit(1);
+			}
+			if (ret == 1) {
+				fprintf(stderr, "%s is mounted\n", file);
+				exit(1);
+			}
 		}
 		fd = open(file, O_RDWR);
 		if (fd < 0) {