1 files changed, 14 insertions, 0 deletions
diff --git a/compiler/main/Annotations.hs b/compiler/main/Annotations.hs
index 277c059b11..ec179d86e2 100644
--- a/compiler/main/Annotations.hs
+++ b/compiler/main/Annotations.hs
@@ -16,6 +16,7 @@ module Annotations (
         deserializeAnns
     ) where
 
+import Binary
 import Module           ( Module )
 import Name
 import Outputable
@@ -64,6 +65,19 @@ instance Outputable name => Outputable (AnnTarget name) where
     ppr (NamedTarget nm) = text "Named target" <+> ppr nm
     ppr (ModuleTarget mod) = text "Module target" <+> ppr mod
 
+instance Binary name => Binary (AnnTarget name) where
+    put_ bh (NamedTarget a) = do
+        putByte bh 0
+        put_ bh a
+    put_ bh (ModuleTarget a) = do
+        putByte bh 1
+        put_ bh a
+    get bh = do
+        h <- getByte bh
+        case h of
+            0 -> get bh >>= (return . NamedTarget)
+            _ -> get bh >>= (return . ModuleTarget)
+
 instance Outputable Annotation where
     ppr ann = ppr (ann_target ann)