diff --git a/mtkclient/Library/DA/xflash/xflash_lib.py b/mtkclient/Library/DA/xflash/xflash_lib.py
index ce857cb..54a69ec 100755
--- a/mtkclient/Library/DA/xflash/xflash_lib.py
+++ b/mtkclient/Library/DA/xflash/xflash_lib.py
@@ -1119,11 +1119,11 @@ class DAXFlash(metaclass=LogBase):
                 if self.daconfig.emi is None:
                     emmc_info = self.get_emmc_info(False)
                     if emmc_info is not None and emmc_info.user_size != 0:
-                        self.info("DRAM config needed for : " + hexlify(emmc_info.cid[:8]).decode('utf-8'))
+                        self.info(f"DRAM config needed for : {hexlify(emmc_info.cid[:8]).decode('utf-8')}")
                     else:
                         ufs_info = self.get_ufs_info()
                         if ufs_info is not None and ufs_info.block_size != 0:
-                            self.info("DRAM config needed for : " + hexlify(ufs_info.cid).decode('utf-8'))
+                            self.info(f"DRAM config needed for : {hexlify(ufs_info.cid).decode('utf-8')}")
                     self.info("No preloader given. Searching for preloader")
                     found = False
                     for root, dirs, files in os.walk(os.path.join(self.pathconfig.get_loader_path(), 'Preloader')):
@@ -1188,7 +1188,7 @@ class DAXFlash(metaclass=LogBase):
                     self.error("Error on booting to da (xflash)")
                     return False
             else:
-                self.error("Didn't get brom connection, got instead: " + hexlify(connagent).decode('utf-8'))
+                self.error(f"Didn't get brom connection, got instead: {hexlify(connagent).decode('utf-8')}")
         return False
 
 
diff --git a/mtkclient/Library/DA/xml/extension/v6.py b/mtkclient/Library/DA/xml/extension/v6.py
index bc837f0..6dbf1dd 100755
--- a/mtkclient/Library/DA/xml/extension/v6.py
+++ b/mtkclient/Library/DA/xml/extension/v6.py
@@ -377,7 +377,7 @@ class xmlflashext(metaclass=LogBase):
                         self.error("Couldn't read rpmb.")
                         return False
                     wf.write(data)
-            self.info("Done reading rpmb to " + filename)
+            self.info(f"Done reading rpmb to {filename}")
             return True
         return False
 
diff --git a/mtkclient/Library/Hardware/hwcrypto.py b/mtkclient/Library/Hardware/hwcrypto.py
index d43b1f3..341a2f5 100755
--- a/mtkclient/Library/Hardware/hwcrypto.py
+++ b/mtkclient/Library/Hardware/hwcrypto.py
@@ -108,7 +108,7 @@ class hwcrypto(metaclass=LogBase):
             elif mode == "sha256":
                 return self.dxcc.generate_sha256(data=data)
         else:
-            self.error("Unknown aes_hwcrypt type: " + btype)
+            self.error(f"Unknown aes_hwcrypt type: {btype}")
             self.error("aes_hwcrypt supported types are: sej")
             return bytearray()