diff --git a/src/Z80/Operations.hs b/src/Z80/Operations.hs
index 01542a9..205fde9 100644
--- a/src/Z80/Operations.hs
+++ b/src/Z80/Operations.hs
@@ -849,6 +849,7 @@ instance EncodeReg16 AF where
 class EncodeReg16 r => Reg16 r
 instance Reg16 BC
 instance Reg16 DE
+instance Reg16 HL
 
 instance EncodeReg16 RegIx where
   encodeReg16 IX = 0xdd