diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,5 +1,11 @@
 # Revision history for net-spider-pangraph
 
+## 0.2.0.0  -- 2019-12-28
+
+* Remove `ToAttributes` instance of `PropertyMap`s, because they are
+  now deprecated.
+* Add `ToAttributes` instance to `PMap`.
+
 ## 0.1.1.1  -- 2019-10-04
 
 * Confirm test with `hashable-1.3.0.0`.
diff --git a/net-spider-pangraph.cabal b/net-spider-pangraph.cabal
--- a/net-spider-pangraph.cabal
+++ b/net-spider-pangraph.cabal
@@ -1,5 +1,5 @@
 name:                   net-spider-pangraph
-version:                0.1.1.1
+version:                0.2.0.0
 author:                 Toshio Ito <debug.ito@gmail.com>
 maintainer:             Toshio Ito <debug.ito@gmail.com>
 license:                BSD3
@@ -23,12 +23,12 @@
                         NetSpider.Pangraph.Atom
   -- other-modules:        
   build-depends:        base >=4.11.1.0 && <4.13,
-                        net-spider >=0.3.1.0 && <0.4,
+                        net-spider >=0.4.0.0 && <0.5,
                         bytestring >=0.10.8.2 && <0.11,
                         text >=1.2.3.1 && <1.3,
                         pangraph >=0.2.1 && <0.3,
                         time >=1.8.0.2 && <1.10,
-                        greskell >=0.2.3.0 && <0.3
+                        greskell >=1.0.0.0 && <1.1
 
 -- executable net-spider-pangraph
 --   default-language:     Haskell2010
diff --git a/src/NetSpider/Pangraph.hs b/src/NetSpider/Pangraph.hs
--- a/src/NetSpider/Pangraph.hs
+++ b/src/NetSpider/Pangraph.hs
@@ -6,8 +6,7 @@
 --
 -- Conversion of NetSpider data model into Pangraph data model. This
 -- module allows you to export a snapshot graph ('SnapshotNode's and
--- 'SnapshotLink's) to 'P.Pangraph'. Then you can export it to a
--- GraphML file so that external tools can handle it.
+-- 'SnapshotLink's) to 'P.Pangraph'.
 module NetSpider.Pangraph
        ( -- * Converters
          makePangraph,
@@ -30,7 +29,8 @@
 
 import Data.ByteString (ByteString)
 import qualified Data.ByteString as BS
-import Data.Greskell.Graph (PropertyMap(allProperties), Property(..))
+import Data.Foldable (Foldable)
+import Data.Greskell.PMap (PMap, pMapToList)
 import Data.Text (pack)
 import Data.Text.Encoding (encodeUtf8)
 import Data.Time.LocalTime (TimeZone(..))
@@ -119,10 +119,9 @@
 instance (ToAtom k, ToAtom v) => ToAttributes [(k,v)] where
   toAttributes = map (\(k, v) -> (toAtom k, toAtom v))
 
-instance (PropertyMap m, Property p, ToAtom v) => ToAttributes (m p v) where
-  toAttributes = toAttributes . map toPair . allProperties
-    where
-      toPair p = (propertyKey p, propertyValue p)
+-- | @since 0.2.0.0
+instance (Foldable c, ToAtom v) => ToAttributes (PMap c v) where
+  toAttributes = toAttributes . pMapToList
 
 -- | 'Nothing' is mapped to empty attributes.
 instance ToAttributes a => ToAttributes (Maybe a) where