diff --git a/src/systems/si-fps/CMakeLists.txt b/src/systems/si-fps/CMakeLists.txt
index 983a54db..ffd302de 100644
--- a/src/systems/si-fps/CMakeLists.txt
+++ b/src/systems/si-fps/CMakeLists.txt
@@ -24,7 +24,7 @@ cmake_minimum_required(VERSION 3.19)
 
 add_units_module(
     si-fps
-    DEPENDENCIES mp-units::si
+    DEPENDENCIES mp-units::si-international
     HEADERS include/units/isq/si/fps/acceleration.h
             include/units/isq/si/fps/area.h
             include/units/isq/si/fps/density.h
diff --git a/src/systems/si-fps/include/units/isq/si/fps/length.h b/src/systems/si-fps/include/units/isq/si/fps/length.h
index a4307180..c33819cd 100644
--- a/src/systems/si-fps/include/units/isq/si/fps/length.h
+++ b/src/systems/si-fps/include/units/isq/si/fps/length.h
@@ -29,24 +29,21 @@
 #include <units/symbol_text.h>
 // IWYU pragma: end_exports
 
-#include <units/isq/si/length.h>
+#include <units/isq/si/international/length.h>
 #include <units/unit.h>
 
 namespace units::isq::si::fps {
 
 // https://en.wikipedia.org/wiki/Foot_(unit)
-struct foot : named_scaled_unit<foot, "ft", no_prefix, ratio(3'048, 1'000, -1), si::metre> {};
-
-struct inch : named_scaled_unit<inch, "in", no_prefix, ratio(1, 12), foot> {};
+using si::international::fathom;
+using si::international::foot;
+using si::international::inch;
+using si::international::mil;
+using si::international::thou;
+using si::international::yard;
 
 // thousandth of an inch
-struct thousandth : named_scaled_unit<thousandth, "thou", no_prefix, ratio(1, 1'000), inch> {};
-struct thou : alias_unit<thousandth, "thou", no_prefix> {};
-struct mil : alias_unit<thousandth, "mil", no_prefix> {};
-
-struct yard : named_scaled_unit<yard, "yd", si::prefix, ratio(3, 1), foot> {};
-
-struct fathom : named_scaled_unit<fathom, "ftm", no_prefix, ratio(6, 1), foot> {};
+struct thousandth : alias_unit<thou, "thou", no_prefix> {};
 
 struct kiloyard : prefixed_unit<kiloyard, si::kilo, yard> {};