diff --git a/src/json.hpp b/src/json.hpp
index 64ca73b81..44626657c 100755
--- a/src/json.hpp
+++ b/src/json.hpp
@@ -1994,8 +1994,9 @@ class basic_json
         }
 
         // We only reach this line if we cannot compare values. In that case,
-        // we compare types.
-        return lhs_type < rhs_type;
+        // we compare types. Have to use operator< explicitly in order to
+        // not cause ambiguity on MS compiler
+        return operator<(lhs_type, rhs_type);
     }
 
     /// comparison: less than or equal
diff --git a/test/unit.cpp b/test/unit.cpp
index cedcb9ba8..ddff76039 100644
--- a/test/unit.cpp
+++ b/test/unit.cpp
@@ -6202,7 +6202,7 @@ 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] );
                 }
             }
         }