diff --git a/src/JSON.cc b/src/JSON.cc
index 44bc1c1f..07bb729d 100644
--- a/src/JSON.cc
+++ b/src/JSON.cc
@@ -1429,6 +1429,7 @@ bool JSON::iterator::operator==(const JSON::iterator& o) const
             }
             default:
             {
+                // not sure if used
                 break;
             }
         }
diff --git a/test/JSON_unit.cc b/test/JSON_unit.cc
index ebabd115..6513d6bd 100644
--- a/test/JSON_unit.cc
+++ b/test/JSON_unit.cc
@@ -1412,10 +1412,12 @@ TEST_CASE("Iterators")
         CHECK(i4 == i4);
     }
     {
-        JSON j_object = {{"1", 1}, {"2", 2}};
+        JSON j_object = {{"1", 1}, {"2", 2}, {"3", 3}};
 
         JSON::iterator i1 = j_object.begin();
         ++i1;
+        JSON::iterator i11 = j_object.begin();
+        CHECK((i1 == i11) == false);
         JSON::iterator i2(i1);
         JSON::iterator i3;
         i3 = i2;