diff --git a/auth_algo.cpp b/auth_algo.cpp
index b71636b..f062b0f 100644
--- a/auth_algo.cpp
+++ b/auth_algo.cpp
@@ -11,7 +11,8 @@
 namespace rakp_auth
 {
 
-std::vector<uint8_t> AlgoSHA1::generateHMAC(std::vector<uint8_t>& input) const
+std::vector<uint8_t> AlgoSHA1::generateHMAC(
+        const std::vector<uint8_t>& input) const
 {
     std::vector<uint8_t> output(SHA_DIGEST_LENGTH);
     unsigned int mdLen = 0;
@@ -26,7 +27,8 @@
     return output;
 }
 
-std::vector<uint8_t> AlgoSHA1::generateICV(std::vector<uint8_t>& input) const
+std::vector<uint8_t> AlgoSHA1::generateICV(
+        const std::vector<uint8_t>& input) const
 {
     std::vector<uint8_t> output(SHA_DIGEST_LENGTH);
     unsigned int mdLen = 0;