diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,8 @@
+aeson-diff 1.1.0.14
+
+    * Fix pointer application after json roundtrip
+      https://github.com/clintonmead/aeson-diff/pull/13
+
 aeson-diff 1.1.0.5
 
     * Support GHC-8.4.x in recent Stackage releases.
diff --git a/aeson-diff.cabal b/aeson-diff.cabal
--- a/aeson-diff.cabal
+++ b/aeson-diff.cabal
@@ -1,5 +1,5 @@
 name:                aeson-diff
-version:             1.1.0.13
+version:             1.1.0.14
 synopsis:            Extract and apply patches to JSON documents.
 description:
   .
@@ -34,7 +34,7 @@
   exposed-modules:     Data.Aeson.Diff
                      , Data.Aeson.Patch
                      , Data.Aeson.Pointer
-  build-depends:       base >=4.11.1 && <4.17
+  build-depends:       base >=4.11.1 && <5
                      , aeson >= 2.0.3
                      , bytestring >= 0.10
                      , edit-distance-vector
@@ -47,7 +47,7 @@
   hs-source-dirs:      src
   main-is:             diff.hs
   other-modules:       Codec
-  build-depends:       base
+  build-depends:       base <5
                      , aeson >= 2.0.3
                      , aeson-diff
                      , bytestring
@@ -59,7 +59,7 @@
   hs-source-dirs:      src
   main-is:             patch.hs
   other-modules:       Codec
-  build-depends:       base
+  build-depends:       base <5
                      , aeson >= 2.0.3
                      , aeson-diff
                      , bytestring
@@ -71,7 +71,7 @@
   type:                exitcode-stdio-1.0
   hs-source-dirs:      test
   main-is:             properties.hs
-  build-depends:       base
+  build-depends:       base <5
                      , QuickCheck
                      , aeson >= 2.0.3
                      , aeson-diff
@@ -83,7 +83,7 @@
   type:                exitcode-stdio-1.0
   hs-source-dirs:      test
   main-is:             examples.hs
-  build-depends:       base
+  build-depends:       base <5
                      , Glob
                      , aeson >= 2.0.3
                      , aeson-diff
@@ -97,7 +97,7 @@
   type:                exitcode-stdio-1.0
   ghc-options:         -threaded
   main-is:             doctests.hs
-  build-depends:       base
+  build-depends:       base <5
                      , doctest >= 0.18.2
   other-modules:       Build_doctests
   autogen-modules:     Build_doctests
diff --git a/lib/Data/Aeson/Diff.hs b/lib/Data/Aeson/Diff.hs
--- a/lib/Data/Aeson/Diff.hs
+++ b/lib/Data/Aeson/Diff.hs
@@ -34,7 +34,7 @@
 import           Data.Vector.Distance       (Params(Params, equivalent, positionOffset, substitute, insert, delete, cost), leastChanges)
 
 import Data.Aeson.Patch                     (Operation(Add, Cpy, Mov, Rem, Rep, Tst), Patch(Patch), changePointer, changeValue, modifyPointer)
-import Data.Aeson.Pointer                   (Key(AKey, OKey), Pointer(Pointer), formatPointer, get, pointerFailure, pointerPath)
+import Data.Aeson.Pointer                   (Key(AKey, OKey), Pointer(Pointer), formatPointer, get, pointerFailure, pointerPath, toAesonKey)
 
 -- * Configuration
 
@@ -243,10 +243,11 @@
             fn Nothing  = cannot "insert" "array" i pointer
             fn (Just d) = Just <$> go (Pointer path) v' d
         in Array <$> vModify i fn v
-    go (Pointer [OKey n]) v' (Object m) =
-        return . Object $ HM.insert n v' m
-    go (Pointer (OKey n : path)) v' (Object o) =
-        let fn :: Maybe Value -> Result (Maybe Value)
+    go (Pointer [key]) v' (Object m) =
+        return . Object $ HM.insert (toAesonKey key) v' m
+    go (Pointer (key : path)) v' (Object o) =
+        let n = toAesonKey key
+            fn :: Maybe Value -> Result (Maybe Value)
             fn Nothing  = cannot "insert" "object" n pointer
             fn (Just d) = Just <$> go (Pointer path) v' d
         in Object <$> hmModify n fn o
@@ -273,13 +274,15 @@
             fn Nothing  = cannot "traverse" "array" i from
             fn (Just o) = Just <$> go path o
         in Array <$> vModify i fn v
-    go [OKey n] (Object m) =
-        let fn :: Maybe Value -> Result (Maybe Value)
+    go [key] (Object m) =
+        let n = toAesonKey key
+            fn :: Maybe Value -> Result (Maybe Value)
             fn Nothing  = cannot "delete" "object" n from
             fn (Just _) = return Nothing
         in Object <$> hmModify n fn m
-    go (OKey n : path) (Object m) =
-        let fn :: Maybe Value -> Result (Maybe Value)
+    go (key : path) (Object m) =
+        let n = toAesonKey key
+            fn :: Maybe Value -> Result (Maybe Value)
             fn Nothing  = cannot "traverse" "object" n from
             fn (Just o) = Just <$> go path o
         in Object <$> hmModify n fn m
diff --git a/lib/Data/Aeson/Pointer.hs b/lib/Data/Aeson/Pointer.hs
--- a/lib/Data/Aeson/Pointer.hs
+++ b/lib/Data/Aeson/Pointer.hs
@@ -10,13 +10,14 @@
   formatPointer,
   parsePointer,
   -- * Using pointers
+  toAesonKey,
   get,
   pointerFailure,
 ) where
 
 import           Data.Aeson (encode)
 import qualified Data.Aeson.Key (Key)
-import           Data.Aeson.Key (fromText, toText)
+import           Data.Aeson.Key (fromText, fromString, toText)
 import qualified Data.Aeson.KeyMap as HM
 import           Data.Aeson.Types (FromJSON(parseJSON), Parser, Result(Error), ToJSON(toJSON), Value(Array, Object, Number, String), modifyFailure)
 import qualified Data.ByteString.Lazy.Char8 as BS
@@ -35,6 +36,14 @@
     | AKey Int                -- ^ Traverse a 'Value' with an 'Array' constructor.
   deriving (Eq, Ord, Show, Generic)
 
+-- | Convert a path component to a JSON object key.
+toAesonKey :: Key -> Data.Aeson.Key.Key
+toAesonKey key = case key of
+  OKey x -> x
+  -- According to https://datatracker.ietf.org/doc/html/rfc6901#section-4
+  -- strings containing numbers are valid to reference in an object.
+  AKey x -> fromString $ show x
+
 instance ToJSON Key where
     toJSON (OKey t) = toJSON t
     toJSON (AKey a) = Number . fromInteger . toInteger $ a
@@ -131,8 +140,8 @@
 get (Pointer []) v = return v
 get (Pointer (AKey i : path)) (Array v) =
   maybe (fail "") return (v V.!? i) >>= get (Pointer path)
-get (Pointer (OKey n : path)) (Object v) =
-  maybe (fail "") return (HM.lookup n v) >>= get (Pointer path)
+get (Pointer (key : path)) (Object v) =
+  maybe (fail "") return (HM.lookup (toAesonKey key) v) >>= get (Pointer path)
 get pointer value = pointerFailure pointer value
 
 -- | Report an error while following a pointer.