diff --git a/src/http_response.cpp b/src/http_response.cpp
index 75d1082b..0d111255 100644
--- a/src/http_response.cpp
+++ b/src/http_response.cpp
@@ -207,7 +207,7 @@ namespace details
 
 ssize_t cb(void* cls, uint64_t pos, char* buf, size_t max)
 {
-    ssize_t val = static_cast<http_response*>(cls)->cycle_callback(buf);
+    ssize_t val = static_cast<http_response*>(cls)->cycle_callback(buf, max);
     if(val == -1)
         static_cast<http_response*>(cls)->completed = true;
     return val;
diff --git a/src/httpserver/http_response.hpp b/src/httpserver/http_response.hpp
index d7b57df3..942bf1c8 100644
--- a/src/httpserver/http_response.hpp
+++ b/src/httpserver/http_response.hpp
@@ -62,7 +62,7 @@ class bad_caching_attempt: public std::exception
     }
 };
 
-typedef ssize_t(*cycle_callback_ptr)(const std::string&);
+typedef ssize_t(*cycle_callback_ptr)(char*, size_t);
 
 /**
  * Class representing an abstraction for an Http Response. It is used from classes using these apis to send information through http protocol.