diff --git a/Sources/Units/Units.swift b/Sources/Units/Units.swift
index 8d53644..879d02f 100644
--- a/Sources/Units/Units.swift
+++ b/Sources/Units/Units.swift
@@ -343,8 +343,8 @@ public struct UnitValue<ValueType: ConvertibleToDouble>:
 	}
 
 	/// The result will have the `unit` of the left hand side value.
-	public static func - <T: ConvertibleToDouble>(
-		lhs: UnitValue<T>, rhs: UnitValue<T>
+	public static func - <L: ConvertibleToDouble, R: ConvertibleToDouble>(
+		lhs: UnitValue<L>, rhs: UnitValue<R>
 	)
 		-> UnitValue<Double>
 	{
@@ -352,8 +352,8 @@ public struct UnitValue<ValueType: ConvertibleToDouble>:
 	}
 
 	/// The result will have the `unit` of the left hand side value.
-	public static func + <T: ConvertibleToDouble>(
-		lhs: UnitValue<T>, rhs: UnitValue<T>
+	public static func + <L: ConvertibleToDouble, R: ConvertibleToDouble>(
+		lhs: UnitValue<L>, rhs: UnitValue<R>
 	)
 		-> UnitValue<Double>
 	{
@@ -361,8 +361,8 @@ public struct UnitValue<ValueType: ConvertibleToDouble>:
 	}
 
 	/// The result will have the `unit` of the left hand side value.
-	public static func * <T: ConvertibleToDouble>(
-		lhs: UnitValue<T>, rhs: UnitValue<T>
+	public static func * <L: ConvertibleToDouble, R: ConvertibleToDouble>(
+		lhs: UnitValue<L>, rhs: UnitValue<R>
 	)
 		-> UnitValue<Double>
 	{
@@ -370,8 +370,8 @@ public struct UnitValue<ValueType: ConvertibleToDouble>:
 	}
 
 	/// The result will have the `unit` of the left hand side value.
-	public static func / <T: ConvertibleToDouble>(
-		lhs: UnitValue<T>, rhs: UnitValue<T>
+	public static func / <L: ConvertibleToDouble, R: ConvertibleToDouble>(
+		lhs: UnitValue<L>, rhs: UnitValue<R>
 	)
 		-> UnitValue<Double>
 	{