diff --git a/src/Makefile b/src/Makefile
index fe3eacb..893bb75 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -15,7 +15,7 @@ ifneq ($(MAKECMDGOALS),clean)
     -include $(DEPENDS)
 endif
 
-.PHONY: install uninstall clean
+.PHONY: all install uninstall clean
 
 all: $(TARGET)
 
diff --git a/src/types.cc b/src/types.cc
index b2249b5..6b340fa 100644
--- a/src/types.cc
+++ b/src/types.cc
@@ -1,28 +1,63 @@
 #include "types.hh"
 
+#include <pEp/status_to_string.hh> // from libpEpAdapter
 /*
 #include <pEp/pEpEngine.h>
 #include <pEp/stringpair.h>
 #include <pEp/message.h>
 */
 
+#include <string>
+
 namespace pEp
 {
+    EngineError::EngineError(PEP_STATUS status, const char* message)
+    : std::runtime_error(
+        std::string{"EngineError: "}
+        + (message ? '"' + std::string{message} + "\" " : std::string{} )
+        + status_to_string(status)
+      )
+    {}
 
-    template class Wrapper<::pEp_identity>;
-    template class Wrapper<::stringpair_t>;
-    
-    template class Wrapper<::message>;
 
     template<>
     template<>
     message* Wrapper<::message*>::_new<PEP_msg_direction, char*>(PEP_msg_direction dir, char* s)
     {
         message* m = new_message(dir);
+        if(!m)
+        {
+            throw EngineError(PEP_OUT_OF_MEMORY, "new_message()");
+        }
         return m;
     }
 
+    template<>
+    template<>
+    ::stringpair_t* Wrapper<::stringpair_t*>::_new(const char* key, const char* value)
+    {
+        stringpair_t* sp = new_stringpair(key, value);
+        if(!sp)
+        {
+            throw EngineError(PEP_OUT_OF_MEMORY, "new_stringpair()");
+        }
+        return sp;
+    }
+
+    template<>
+    template<>
+    ::stringpair_t* Wrapper<::stringpair_t*>::_new(const std::string& key, const std::string& value)
+    {
+        return Wrapper<::stringpair_t*>::_new(key.c_str(), value.c_str());
+    }
+
 
     Message m(PEP_dir_incoming, "Foo");
+    StringPair sp(std::string("foo"), std::string("bar"));
+
+    template class Wrapper<::pEp_identity>;
+    template class Wrapper<::stringpair_t>;
     
+    template class Wrapper<::message>;
+
 } // end of namespace pEp
diff --git a/src/types.hh b/src/types.hh
index b8148b4..809884e 100644
--- a/src/types.hh
+++ b/src/types.hh
@@ -6,12 +6,18 @@
 
 #include "wrapper.hh"
 
+#include <stdexcept>
 #include <pEp/pEpEngine.h>
 #include <pEp/stringpair.h>
 #include <pEp/message.h>
 
 namespace pEp
 {
+    class EngineError : std::runtime_error
+    {
+    public:
+        EngineError(PEP_STATUS status, const char* message = nullptr);
+    };
 
     using Identity = Wrapper<::pEp_identity>;
     using StringPair = Wrapper<::stringpair_t>;