diff --git a/linux/os.h b/linux/os.h
index 8055f7ab..e3cfc09e 100644
--- a/linux/os.h
+++ b/linux/os.h
@@ -32,12 +32,9 @@ along with sedutil.  If not, see <http://www.gnu.org/licenses/>.
 // a few OS specific methods that need to be worked out
 #define SNPRINTF snprintf
 // Cumbersome, but trying to avoid editing common files. If /sys/block is not present, reverts to enumerating /dev/sd* devices. 
-#define DEVICEMASK switch(DtaDevOS::getNextDevice(i)) {
-    case 1 : snprintf(devname,23,"/dev/%s",DtaDevOS::getDeviceName()); 
-        break;
-    case -1 : snprintf(devname,23,"/dev/sd%c",'a'+i); 
-        break;
-    default : snprintf(devname,23,"/dev/sdX"); 
-        break;
+#define DEVICEMASK switch(DtaDevOS::getNextDevice(i)) { \
+    case 1 : snprintf(devname,23,"/dev/%s",DtaDevOS::getDeviceName()); break; \
+    case -1 : snprintf(devname,23,"/dev/sd%c",'a'+i); break; \
+    default : snprintf(devname,23,"/dev/sdX"); break; \ 
 }
 #define DEVICEEXAMPLE "/dev/sdc"