diff --git a/src/include/units/physical/si/substance.h b/src/include/units/physical/si/substance.h
index e3d0348e..a28f51ba 100644
--- a/src/include/units/physical/si/substance.h
+++ b/src/include/units/physical/si/substance.h
@@ -28,7 +28,7 @@
 
 namespace units::physical::si {
 
-struct mole : named_unit<metre, "mol", prefix> {};
+struct mole : named_unit<mole, "mol", prefix> {};
 
 struct dim_substance : physical::dim_substance<mole> {};