diff --git a/export.cpp b/export.cpp
index 58f3220..d01a961 100644
--- a/export.cpp
+++ b/export.cpp
@@ -165,6 +165,8 @@ IT& to(const object& obj, IT& it, int tab)
 			return vector_to(obj, it, tab);
 		case Map:
 			return map_to(obj, it, tab);
+		default:
+			throw std::runtime_error("Unknown value_type");
 	}
 	return it;
 }
diff --git a/import.hpp b/import.hpp
index 58a75a4..1f76744 100644
--- a/import.hpp
+++ b/import.hpp
@@ -1,6 +1,7 @@
 #ifndef TOKOX_CPP_JSON_IMPORT_HPP
 #define TOKOX_CPP_JSON_IMPORT_HPP
 
+#include <stdexcept>
 #include "object.hpp"
 
 namespace tokox::json
@@ -35,7 +36,7 @@ class import_error : public std::exception
 			case VALUE_NOT_IMPLEMENTED:
 				return "Value not implemented!";
 			default:
-				return "Unknown error!";
+				throw std::runtime_error("Unknown error_type!");
 		}
 	}
 private: