diff --git a/src/json.hpp b/src/json.hpp
old mode 100644
new mode 100755
index 269042f89..319f541cb
--- a/src/json.hpp
+++ b/src/json.hpp
@@ -4286,7 +4286,9 @@ class basic_json
 
         // We only reach this line if we cannot compare values. In that case,
         // we compare types.
-        return lhs_type < rhs_type;
+        // Have to use operator< explicitly in order to
+        // not cause ambiguity on MS compiler
+        return operator<(lhs_type, rhs_type);
     }
 
     /*!
diff --git a/test/unit.cpp b/test/unit.cpp
old mode 100644
new mode 100755
index e38305190..27731b330
--- a/test/unit.cpp
+++ b/test/unit.cpp
@@ -6939,7 +6939,7 @@ TEST_CASE("lexicographical comparison operators")
                     CAPTURE(i);
                     CAPTURE(j);
                     // check precomputed values
-                    CHECK( (j_types[i] < j_types[j]) == expected[i][j] );
+                    CHECK(operator<(j_types[i], j_types[j]) == expected[i][j]);
                 }
             }
         }