diff --git a/src/attributes.hpp b/src/attributes.hpp
index 62b1710..2991a95 100644
--- a/src/attributes.hpp
+++ b/src/attributes.hpp
@@ -19,6 +19,8 @@
 #include <map>
 #include <string>
 
+#include <boost/concept/assert.hpp>
+#include <boost/concept_check.hpp>
 #include <boost/shared_ptr.hpp>
 
 //!
@@ -47,6 +49,7 @@ public:
     //!
     explicit attribute(T &object)
         : reference(object) {
+            BOOST_CONCEPT_ASSERT((boost::Assignable<T>));
     }
 
     //!
diff --git a/src/string2type.hpp b/src/string2type.hpp
index 67d9fdc..3d04c3f 100644
--- a/src/string2type.hpp
+++ b/src/string2type.hpp
@@ -16,6 +16,8 @@
 
 #include <string>
 
+#include <boost/concept/assert.hpp>
+#include <boost/concept_check.hpp>
 #include <boost/lexical_cast.hpp>
 
 namespace string2type {
@@ -25,6 +27,8 @@ namespace string2type {
 //!
 template<typename T>
 T convert(const std::string &value) {
+    BOOST_CONCEPT_ASSERT((boost::Assignable<T>));
+
     return boost::lexical_cast<T>(value);
 }