diff --git a/src/mastodon-cpp.cpp b/src/mastodon-cpp.cpp
index f46d6fc..78db8bc 100644
--- a/src/mastodon-cpp.cpp
+++ b/src/mastodon-cpp.cpp
@@ -25,7 +25,7 @@
 #include "mastodon-cpp.hpp"
 
 using namespace Mastodon;
-return_base::operator const bool() const
+return_base::operator bool()
 {
     if (error_code == 0)
     {
@@ -37,7 +37,7 @@ return_base::operator const bool() const
     }
 }
 
-return_base::operator const uint8_t() const
+return_base::operator uint8_t()
 {
     return error_code;
 }
@@ -47,7 +47,7 @@ return_call::operator const string() const
     return answer;
 }
 
-std::ostream &Mastodon::operator <<(std::ostream &out, const return_call &ret)
+std::ostream &operator <<(std::ostream &out, const return_call &ret)
 {
     out << ret.answer;
     return out;
diff --git a/src/mastodon-cpp.hpp b/src/mastodon-cpp.hpp
index 600e539..58404fc 100644
--- a/src/mastodon-cpp.hpp
+++ b/src/mastodon-cpp.hpp
@@ -47,8 +47,8 @@ namespace Mastodon
         uint8_t error_code = 0;     // NOTE: http://mazack.org/unix/errno.php
         string error_message;
 
-        operator const bool() const;
-        operator const uint8_t() const;
+        operator bool();
+        operator uint8_t();
     } return_base;
 
     /*!