diff --git a/conanfile.py b/conanfile.py
index 83df621e..dce9b515 100644
--- a/conanfile.py
+++ b/conanfile.py
@@ -144,10 +144,11 @@ class UnitsConan(ConanFile):
         self.cpp_info.components["si"].requires = ["isq"]
         self.cpp_info.components["si-cgs"].requires = ["si"]
         self.cpp_info.components["si-fps"].requires = ["si"]
+        self.cpp_info.components["si-hep"].requires = ["si"]
         self.cpp_info.components["si-iau"].requires = ["si"]
         self.cpp_info.components["si-imperial"].requires = ["si"]
         self.cpp_info.components["si-international"].requires = ["si"]
         self.cpp_info.components["si-typographic"].requires = ["si"]
         self.cpp_info.components["si-uscs"].requires = ["si"]
         self.cpp_info.components["isq-iec80000"].requires = ["si"]
-        self.cpp_info.components["systems"].requires = ["isq", "isq-natural", "si", "si-cgs", "si-fps", "si-iau", "si-imperial", "si-international", "si-typographic", "si-uscs", "isq-iec80000"]
+        self.cpp_info.components["systems"].requires = ["isq", "isq-natural", "si", "si-cgs", "si-fps", "si-hep", "si-iau", "si-imperial", "si-international", "si-typographic", "si-uscs", "isq-iec80000"]
diff --git a/src/systems/si-hep/include/units/isq/si/hep/area.h b/src/systems/si-hep/include/units/isq/si/hep/area.h
index 2244ffab..fa5d8bdb 100644
--- a/src/systems/si-hep/include/units/isq/si/hep/area.h
+++ b/src/systems/si-hep/include/units/isq/si/hep/area.h
@@ -47,9 +47,6 @@ struct nano_barn : prefixed_unit<nano_barn, nano, barn> {};
 struct micro_barn : prefixed_unit<micro_barn, micro, barn> {};
 struct milli_barn : prefixed_unit<milli_barn, milli, barn> {};
 
-//template<UnitOf<dim_area> U, Representation Rep = double>
-//  using area = quantity<dim_area, U, Rep>;
-
 #ifndef UNITS_NO_LITERALS
 
 inline namespace literals {
diff --git a/src/systems/si-hep/include/units/isq/si/hep/energy.h b/src/systems/si-hep/include/units/isq/si/hep/energy.h
index 7fcf36d3..87f8e9dd 100644
--- a/src/systems/si-hep/include/units/isq/si/hep/energy.h
+++ b/src/systems/si-hep/include/units/isq/si/hep/energy.h
@@ -32,9 +32,7 @@
 #include <units/unit.h>
 
 namespace units::isq::si::hep {
-
-// N.B. electron charge (and eV) is an exact constant: https://www.bipm.org/documents/20126/41483022/SI-Brochure-9.pdf#page=147
-struct electronvolt : named_scaled_unit<electronvolt, "eV", prefix, ratio(1'602'176'634, 1'000'000'000, -19), ::units::isq::si::joule> {};
+using units::isq::si::electronvolt;
 
 struct yeV : prefixed_unit<yeV, yocto, electronvolt> {}; // N.B. very rarely used
 struct zeV : prefixed_unit<zeV, zepto, electronvolt> {}; // N.B. very rarely used
@@ -47,7 +45,7 @@ struct meV : prefixed_unit<meV, milli, electronvolt> {};
 using eV = electronvolt;
 struct keV : prefixed_unit<keV, kilo, electronvolt> {};
 struct MeV : prefixed_unit<MeV, mega, electronvolt> {};
-struct GeV : prefixed_unit<MeV, giga, electronvolt> {};
+struct GeV : prefixed_unit<GeV, giga, electronvolt> {};
 struct TeV : prefixed_unit<TeV, tera, electronvolt> {};
 struct PeV : prefixed_unit<PeV, peta, electronvolt> {};
 struct EeV : prefixed_unit<EeV, exa, electronvolt> {}; // N.B. very rarely used