diff --git a/BeefLibs/corlib/src/IComparable.bf b/BeefLibs/corlib/src/IComparable.bf
index 49d75e68..8ad50f28 100644
--- a/BeefLibs/corlib/src/IComparable.bf
+++ b/BeefLibs/corlib/src/IComparable.bf
@@ -18,11 +18,16 @@ namespace System
 		}
 	}
 
-	interface IInteger
+	interface INumeric
+	{
+		static Self operator+(Self lhs, Self rhs);
+	}
+
+	interface IInteger : INumeric
 	{
 	}
 
-	interface IUnsigned
+	interface IUnsigned : INumeric
 	{
 
 	}
diff --git a/BeefLibs/corlib/src/Int64.bf b/BeefLibs/corlib/src/Int64.bf
index c300c6da..0977aa8a 100644
--- a/BeefLibs/corlib/src/Int64.bf
+++ b/BeefLibs/corlib/src/Int64.bf
@@ -17,12 +17,17 @@ namespace System
 
 		public static int operator<=>(Int64 a, Int64 b)
 		{
-			return (int64)a <=> (int64)b;
+			return (SelfBase)a <=> (SelfBase)b;
+		}
+
+		public static Self operator+(Self lhs, Self rhs)
+		{
+			return (SelfBase)lhs + (SelfBase)rhs;
 		}
 
 		public static Int64 operator-(Int64 value)
 		{
-			return (int64)value;
+			return -(SelfBase)value;
 		}
 
 		int IHashable.GetHashCode()
diff --git a/BeefLibs/corlib/src/UInt64.bf b/BeefLibs/corlib/src/UInt64.bf
index 8b19762e..94f6d7d7 100644
--- a/BeefLibs/corlib/src/UInt64.bf
+++ b/BeefLibs/corlib/src/UInt64.bf
@@ -16,7 +16,12 @@ namespace System
 
 		public static int operator<=>(UInt64 a, UInt64 b)
 		{
-			return (uint64)a <=> (uint64)b;
+			return (SelfBase)a <=> (SelfBase)b;
+		}
+
+		public static Self operator+(Self lhs, Self rhs)
+		{
+			return (SelfBase)lhs + (SelfBase)rhs;
 		}
 
 	    int IHashable.GetHashCode()