diff --git a/features/lorawan/mbed_lib.json b/features/lorawan/mbed_lib.json
index 5261112986..b6d1404ba9 100644
--- a/features/lorawan/mbed_lib.json
+++ b/features/lorawan/mbed_lib.json
@@ -82,12 +82,12 @@
             "value": 8
         },
         "fsb-mask": {
-        	"help": "FSB mask for upstream [Only for US915 & AU915] Check lorawan/FSB_Usage.txt for more details",
-        	"value": "{0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0x00FF}"
+            "help": "FSB mask for upstream [Only for US915 & AU915] Check lorawan/FSB_Usage.txt for more details",
+            "value": "{0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0x00FF}"
         },
         "fsb-mask-china": {
-        	"help": "FSB mask for upstream [CN470 PHY] Check lorawan/FSB_Usage.txt for more details",
-        	"value": "{0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF}"
+            "help": "FSB mask for upstream [CN470 PHY] Check lorawan/FSB_Usage.txt for more details",
+            "value": "{0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF}"
         }
     }
 }