1 files changed, 15 insertions, 0 deletions
diff --git a/compiler/main/Annotations.hs b/compiler/main/Annotations.hs
index 277c059b11..7de1a9914b 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
@@ -23,6 +24,7 @@ import Serialized
 import UniqFM
 import Unique
 
+import Control.Monad
 import Data.Maybe
 import Data.Typeable
 import Data.Word        ( Word8 )
@@ -64,6 +66,19 @@ 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 -> liftM NamedTarget  $ get bh
+            _ -> liftM ModuleTarget $ get bh
+
 instance Outputable Annotation where
     ppr ann = ppr (ann_target ann)