diff --git a/.github/workflows/workflow.yml b/.github/workflows/workflow.yml
index e0257d52..c85c70ae 100644
--- a/.github/workflows/workflow.yml
+++ b/.github/workflows/workflow.yml
@@ -27,7 +27,9 @@ jobs:
         - os: ubuntu-latest
           stack-yaml: stack-lts-17.yaml
           extra-args: ""
-
+        - os: ubuntu-latest
+          stack-yaml: stack-nightly.yaml
+          extra-args: ""
     steps:
       - name: Clone project
         uses: actions/checkout@v2
diff --git a/src/Codec/Xlsx/Formatted.hs b/src/Codec/Xlsx/Formatted.hs
index c1b21715..9d39fc36 100644
--- a/src/Codec/Xlsx/Formatted.hs
+++ b/src/Codec/Xlsx/Formatted.hs
@@ -340,7 +340,7 @@ formatCell (row, col) cell = do
     mapM go block
   where
     go :: ((Int, Int), FormattedCell) -> State FormattingState ((Int, Int), Cell)
-    go (pos, c@ FormattedCell{..}) = do
+    go (pos, c@FormattedCell{..}) = do
       styleId <- cellStyleId c
       return (pos, _formattedCell{_cellStyle = styleId})
 
diff --git a/src/Codec/Xlsx/Lens.hs b/src/Codec/Xlsx/Lens.hs
index 67e8bcb0..f15f6912 100644
--- a/src/Codec/Xlsx/Lens.hs
+++ b/src/Codec/Xlsx/Lens.hs
@@ -84,7 +84,7 @@ ixCellRC i = wsCells . ix i
 -- | lens to access cell in a worksheet using more traditional
 -- x+y coordinates
 ixCellXY :: (Int, Int) -> Traversal' Worksheet Cell
-ixCellXY = ixCellRC . swap
+ixCellXY i = ixCellRC $ swap i
 
 -- | accessor that can read, write or delete cell in a worksheet
 -- synonym of 'atCellRC' so uses row+column index
@@ -98,7 +98,7 @@ atCellRC i = wsCells . at i
 -- | lens to read, write or delete cell in a worksheet
 -- using more traditional x+y or row+column index
 atCellXY :: (Int, Int) -> Lens' Worksheet (Maybe Cell)
-atCellXY = atCellRC . swap
+atCellXY i = atCellRC $ swap i
 
 -- | lens to read, write or delete cell value in a worksheet
 -- with row+column coordinates, synonym for 'cellValueRC'
@@ -113,4 +113,4 @@ cellValueAtRC i = atCell i . non def . cellValue
 -- | lens to read, write or delete cell value in a worksheet
 -- using traditional x+y coordinates
 cellValueAtXY :: (Int, Int) -> Lens' Worksheet (Maybe CellValue)
-cellValueAtXY = cellValueAtRC . swap
+cellValueAtXY i = cellValueAtRC $ swap i
diff --git a/src/Codec/Xlsx/Types/Drawing.hs b/src/Codec/Xlsx/Types/Drawing.hs
index 9e42ae8e..1452edf0 100644
--- a/src/Codec/Xlsx/Types/Drawing.hs
+++ b/src/Codec/Xlsx/Types/Drawing.hs
@@ -217,6 +217,21 @@ data Anchor p g = Anchor
     } deriving (Eq, Show, Generic)
 instance (NFData p, NFData g) => NFData (Anchor p g)
 
+data GenericDrawing p g = Drawing
+    { _xdrAnchors :: [Anchor p g]
+    } deriving (Eq, Show, Generic)
+instance (NFData p, NFData g) => NFData (GenericDrawing p g)
+
+-- See 20.5.2.35 "wsDr (Worksheet Drawing)" (p. 3176)
+type Drawing = GenericDrawing FileInfo ChartSpace
+
+type UnresolvedDrawing = GenericDrawing RefId RefId
+
+makeLenses ''Anchor
+makeLenses ''DrawingObject
+makeLenses ''BlipFillProperties
+makeLenses ''GenericDrawing
+
 -- | simple drawing object anchoring using one cell as a top lelft
 -- corner and dimensions of that object
 simpleAnchorXY :: (Int, Int) -- ^ x+y coordinates of a cell used as
@@ -233,21 +248,6 @@ simpleAnchorXY (x, y) sz obj =
   , _anchClientData = def
   }
 
-data GenericDrawing p g = Drawing
-    { _xdrAnchors :: [Anchor p g]
-    } deriving (Eq, Show, Generic)
-instance (NFData p, NFData g) => NFData (GenericDrawing p g)
-
--- See 20.5.2.35 "wsDr (Worksheet Drawing)" (p. 3176)
-type Drawing = GenericDrawing FileInfo ChartSpace
-
-type UnresolvedDrawing = GenericDrawing RefId RefId
-
-makeLenses ''Anchor
-makeLenses ''DrawingObject
-makeLenses ''BlipFillProperties
-makeLenses ''GenericDrawing
-
 {-------------------------------------------------------------------------------
   Default instances
 -------------------------------------------------------------------------------}
diff --git a/stack-nightly.yaml b/stack-nightly.yaml
index 8dba7f85..130b7172 100644
--- a/stack-nightly.yaml
+++ b/stack-nightly.yaml
@@ -1,3 +1,3 @@
-resolver: nightly-2019-10-31
+resolver: nightly-2021-06-19
 packages:
 - '.'
diff --git a/xlsx.cabal b/xlsx.cabal
index c52c7d7a..98e972c3 100644
--- a/xlsx.cabal
+++ b/xlsx.cabal
@@ -26,7 +26,7 @@ Maintainer:          qrilka@gmail.com
 
 Category:            Codec
 Build-type:          Simple
-Tested-with:         GHC == 8.4.4, GHC == 8.6.5, GHC == 8.8.4, GHC == 8.10.4
+Tested-with:         GHC == 8.4.4, GHC == 8.6.5, GHC == 8.8.4, GHC == 8.10.4, GHC == 9.0.1
 Cabal-version:       >=1.10
 
 Flag microlens