diff --git a/src/JSON.cc b/src/JSON.cc
index a8a4022015bee7b52429e53ab55fbeba931f9849..8095a0366d6aa132220801b1e7280b5fc01a47e7 100644
--- a/src/JSON.cc
+++ b/src/JSON.cc
@@ -643,6 +643,7 @@ std::string JSON::parser::parseString() {
     const size_t length = p - _buffer - _pos;
     char* tmp = new char[length + 1];
     std::strncpy(tmp, _buffer + _pos, length);
+    tmp[length] = 0;
     std::string result(tmp);
     delete [] tmp;
 
@@ -838,11 +839,11 @@ JSON::iterator::iterator(JSON* j) : _object(j), _vi(nullptr), _oi(nullptr) {
 JSON::iterator::iterator(const JSON::iterator& o) : _object(o._object), _vi(nullptr), _oi(nullptr) {
     switch (_object->_type) {
         case (array): {
-            _vi = new std::vector<JSON>::iterator(static_cast<std::vector<JSON>*>(_object->_payload)->begin());
+            _vi = new std::vector<JSON>::iterator(*(o._vi));
             break;
         }
         case (object): {
-            _oi = new std::map<std::string, JSON>::iterator(static_cast<std::map<std::string, JSON>*>(_object->_payload)->begin());
+            _oi = new std::map<std::string, JSON>::iterator(*(o._oi));
             break;
         }
         default:
@@ -857,6 +858,18 @@ JSON::iterator::~iterator() {
 
 JSON::iterator& JSON::iterator::operator=(const JSON::iterator& o) {
     _object = o._object;
+    switch (_object->_type) {
+        case (array): {
+            _vi = new std::vector<JSON>::iterator(*(o._vi));
+            break;
+        }
+        case (object): {
+            _oi = new std::map<std::string, JSON>::iterator(*(o._oi));
+            break;
+        }
+        default:
+            break;
+    }
     return *this;
 }
 
@@ -985,11 +998,11 @@ JSON::const_iterator::const_iterator(const JSON* j) : _object(j), _vi(nullptr),
 JSON::const_iterator::const_iterator(const JSON::const_iterator& o) : _object(o._object), _vi(nullptr), _oi(nullptr) {
     switch (_object->_type) {
         case (array): {
-            _vi = new std::vector<JSON>::const_iterator(static_cast<std::vector<JSON>*>(_object->_payload)->begin());
+            _vi = new std::vector<JSON>::const_iterator(*(o._vi));
             break;
         }
         case (object): {
-            _oi = new std::map<std::string, JSON>::const_iterator(static_cast<std::map<std::string, JSON>*>(_object->_payload)->begin());
+            _oi = new std::map<std::string, JSON>::const_iterator(*(o._oi));
             break;
         }
         default:
@@ -1000,11 +1013,11 @@ JSON::const_iterator::const_iterator(const JSON::const_iterator& o) : _object(o.
 JSON::const_iterator::const_iterator(const JSON::iterator& o) : _object(o._object), _vi(nullptr), _oi(nullptr) {
     switch (_object->_type) {
         case (array): {
-            _vi = new std::vector<JSON>::const_iterator(static_cast<std::vector<JSON>*>(_object->_payload)->begin());
+            _vi = new std::vector<JSON>::const_iterator(*(o._vi));
             break;
         }
         case (object): {
-            _oi = new std::map<std::string, JSON>::const_iterator(static_cast<std::map<std::string, JSON>*>(_object->_payload)->begin());
+            _oi = new std::map<std::string, JSON>::const_iterator(*(o._oi));
             break;
         }
         default:
@@ -1019,6 +1032,18 @@ JSON::const_iterator::~const_iterator() {
 
 JSON::const_iterator& JSON::const_iterator::operator=(const JSON::const_iterator& o) {
     _object = o._object;
+    switch (_object->_type) {
+        case (array): {
+            _vi = new std::vector<JSON>::const_iterator(*(o._vi));
+            break;
+        }
+        case (object): {
+            _oi = new std::map<std::string, JSON>::const_iterator(*(o._oi));
+            break;
+        }
+        default:
+            break;
+    }
     return *this;
 }
 
diff --git a/src/JSON.h b/src/JSON.h
index 3a715f70caaee10808f67227d9bfc61287ab9f2a..082a7fcda6f0ebd635eab63e807a5b1c10fce900 100644
--- a/src/JSON.h
+++ b/src/JSON.h
@@ -6,8 +6,8 @@
 #endif
 
 // allow us to use "nullptr" everywhere
-#ifndef nullptr
 #include <cstddef>
+#ifndef nullptr
 #define nullptr NULL
 #endif
 
diff --git a/test/JSON_test.cc b/test/JSON_test.cc
index 3836ba12ddef893ee0c7c9521160cbcb3cc00d2c..f631cfca29a30ab64c81196a944082d4e8188a21 100644
--- a/test/JSON_test.cc
+++ b/test/JSON_test.cc
@@ -202,20 +202,78 @@ void test_array() {
 #endif
 
     // iterators
-    for (JSON::iterator i = a.begin(); i != a.end(); ++i) {
-        std::cerr << *i << '\n';
+    {
+        size_t count = 0;
+        for (JSON::iterator i = a.begin(); i != a.end(); ++i) {
+            std::cerr << *i << '\n';
+            count++;
+        }
+        assert(count == a.size());
+    }
+
+    {
+        /*
+        size_t count = 0;
+        for (JSON::const_iterator i = a.begin(); i != a.end(); ++i) {
+            std::cerr << *i << '\n';
+            count++;
+        }
+        assert(count == a.size());
+        */
     }
 
-    for (JSON::const_iterator i = a.cbegin(); i != a.cend(); ++i) {
-        std::cerr << *i << '\n';
+    {
+        size_t count = 0;
+        for (JSON::const_iterator i = a.cbegin(); i != a.cend(); ++i) {
+            std::cerr << *i << '\n';
+            count++;
+        }
+        assert(count == a.size());
     }
 
 #ifdef __cplusplus11
-    for (auto element : a) {
-        std::cerr << element << '\n';
+    {
+        size_t count = 0;
+        for (auto element : a) {
+            std::cerr << element << '\n';
+            count++;
+        }
+        assert(count == a.size());
     }
 #endif
 
+    {
+        JSON::iterator i;
+        size_t count = 0;
+        for (i = a.begin(); i != a.end(); ++i) {
+            std::cerr << *i << '\n';
+            count++;
+        }
+        assert(count == a.size());
+    }
+
+    {
+        /*
+        JSON::const_iterator i;
+        size_t count = 0;
+        for (i = a.begin(); i != a.end(); ++i) {
+            std::cerr << *i << '\n';
+            count++;
+        }
+        assert(count == a.size());
+        */
+    }
+
+    {
+        JSON::const_iterator i;
+        size_t count = 0;
+        for (i = a.cbegin(); i != a.cend(); ++i) {
+            std::cerr << *i << '\n';
+            count++;
+        }
+        assert(count == a.size());
+    }
+
     {
         // get payload
         std::vector<JSON>* array = static_cast<std::vector<JSON>*>(a.data());