diff --git a/imkey-core/ikc-common/src/apdu.rs b/imkey-core/ikc-common/src/apdu.rs
index 259f433d..6c916d97 100644
--- a/imkey-core/ikc-common/src/apdu.rs
+++ b/imkey-core/ikc-common/src/apdu.rs
@@ -71,6 +71,9 @@ impl BtcApdu {
 
     pub fn btc_sign(index: u8, hash_type: u8, path: &str) -> String {
         let path_bytes = path.as_bytes();
+        if path_bytes.len() as u32 > LC_MAX {
+            panic!("data to long");
+        }
         let mut apdu =
             ApduHeader::new(0x80, 0x42, index, hash_type, path_bytes.len() as u8).to_array();
         apdu.extend(path_bytes.iter());
@@ -364,6 +367,9 @@ impl BtcForkApdu {
 
     pub fn btc_fork_sign(ins: u8, index: u8, hash_type: u8, path: &str) -> String {
         let path_bytes = path.as_bytes();
+        if path_bytes.len() as u32 > LC_MAX {
+            panic!("data to long");
+        }
         let mut apdu =
             ApduHeader::new(0x80, ins, index, hash_type, path_bytes.len() as u8).to_array();
         apdu.extend(path_bytes.iter());
diff --git a/imkey-core/ikc-common/src/constants.rs b/imkey-core/ikc-common/src/constants.rs
index 436f9c8c..a5e08030 100644
--- a/imkey-core/ikc-common/src/constants.rs
+++ b/imkey-core/ikc-common/src/constants.rs
@@ -14,7 +14,7 @@ pub const TSM_ACTION_COS_UPGRADE: &str = "/seCosUpdate";
 pub const TSM_ACTION_COS_CHECK_UPDATE: &str = "/cosCheckUpdate";
 
 //apud related constant
-pub const LC_MAX: u32 = 245;
+pub const LC_MAX: u32 = 239;
 
 pub const ETH_AID: &str = "695F657468";
 pub const EOS_AID: &str = "695F656F73";