diff --git a/src/common.hpp b/src/common.hpp
index ee56cb5..530dcd7 100644
--- a/src/common.hpp
+++ b/src/common.hpp
@@ -3,7 +3,7 @@
 
 #include <string>
 
-enum TokenType
+enum class TokenType
 {
     KEYWORD,
     IDENTIFIER,
@@ -11,7 +11,7 @@ enum TokenType
     ID_OR_LIT
 };
 
-enum ValueType
+enum class ValueType
 {
     STRING,
     NUMBER,
@@ -24,8 +24,8 @@ struct Instruction;
 struct Keyword;
 struct Runtime;
 
-const std::string resolve_TokenType_str(enum TokenType);
-const std::string resolve_ValueType_str(enum ValueType);
+std::string resolve_TokenType_str(enum class TokenType);
+std::string resolve_ValueType_str(enum class ValueType);
 
 
 #endif //BISCUIT_INTERPRETER_COMMON_HPP
diff --git a/src/exceptions.hpp b/src/exceptions.hpp
index 48d806c..a6a4ea5 100644
--- a/src/exceptions.hpp
+++ b/src/exceptions.hpp
@@ -29,9 +29,9 @@ struct WrongArgumentCountExcept : public std::exception
 
 struct WrongTokenExcept : public std::exception
 {
-    enum TokenType expected, got;
+    enum class TokenType expected, got;
     std::string keyword_name, token_str;
-    inline WrongTokenExcept(const std::string& _keyword_name, const std::string& _token_str, const enum TokenType& _expected, const enum TokenType& _got)
+    inline WrongTokenExcept(const std::string& _keyword_name, const std::string& _token_str, enum class TokenType _expected, enum class TokenType _got)
             : expected(_expected), got(_got), keyword_name(_keyword_name), token_str(_token_str) {}
 };
 
@@ -39,9 +39,9 @@ struct WrongTokenExcept : public std::exception
 // Runtime errors
 struct TypeErrorExcept : public std::exception
 {
-    enum ValueType expected, got;
+    enum class ValueType expected, got;
     std::string token_str;
-    inline TypeErrorExcept(const std::string& _token_str, const enum ValueType& _expected, const enum ValueType& _got)
+    inline TypeErrorExcept(const std::string& _token_str, enum class ValueType _expected, enum class ValueType _got)
             : expected(_expected), got(_got), token_str(_token_str) {}
 };
 
diff --git a/src/parse.cpp b/src/parse.cpp
index 7bfdf1f..d9e5010 100644
--- a/src/parse.cpp
+++ b/src/parse.cpp
@@ -279,7 +279,7 @@ Instruction::Instruction(std::vector<Token>& _token_list)
 
 	// Make sure the keyword gets the number of arguments it needs
 	if(keyword_ptr->expected_num_args != -1 && (keyword_ptr->expected_num_args != tokens.size() - 1))
-		throw WrongArgumentCountExcept(keyword_ptr->name, keyword_ptr->expected_num_args, tokens.size() - 1);
+		throw WrongArgumentCountExcept(keyword_ptr->name, keyword_ptr->expected_num_args, static_cast<int>(tokens.size() - 1));
 
 	// Check the arguments supplied are the right kind of tokens
     for(int i = 0; i < keyword_ptr->expected_num_args; i++)
diff --git a/src/util.cpp b/src/util.cpp
index 24d4106..69c13f6 100644
--- a/src/util.cpp
+++ b/src/util.cpp
@@ -1,7 +1,7 @@
 #include "common.hpp"
 #include <string>
 
-const std::string resolve_TokenType_str(enum TokenType ttype)
+std::string resolve_TokenType_str(TokenType ttype)
 {
 	switch(ttype)
 	{
@@ -22,7 +22,7 @@ const std::string resolve_TokenType_str(enum TokenType ttype)
 	return "UNKNOW TOKENTYPE";
 }
 
-const std::string resolve_ValueType_str(enum ValueType vtype)
+std::string resolve_ValueType_str(ValueType vtype)
 {
 	switch(vtype)
 	{