diff --git a/include/xo/unit/quantity2.hpp b/include/xo/unit/quantity2_old.hpp
similarity index 100%
rename from include/xo/unit/quantity2.hpp
rename to include/xo/unit/quantity2_old.hpp
diff --git a/include/xo/unit/quantity.hpp b/include/xo/unit/quantity_.hpp
similarity index 100%
rename from include/xo/unit/quantity.hpp
rename to include/xo/unit/quantity_.hpp
diff --git a/utest/Quantity.test.cpp b/utest/Quantity2.test.cpp
similarity index 100%
rename from utest/Quantity.test.cpp
rename to utest/Quantity2.test.cpp