diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,4 +1,7 @@
 # Changelog for futhask-base
 ## 0.2.0
 Change name of `load` to `loadM`, and add new `load` that emits error instead of wrapping in `Maybe` 
+## 0.2.1
+Fix num_groups context option
+
 ## Unreleased changes
diff --git a/futhask-base.cabal b/futhask-base.cabal
--- a/futhask-base.cabal
+++ b/futhask-base.cabal
@@ -1,7 +1,7 @@
 cabal-version: 1.12
 
 name:           futhask-base
-version:        0.2.0.0
+version:        0.2.1.0
 stability:      experimental
 category:       FFI
 synopsis:       Base library for libraries generated by futhask
diff --git a/src/Futhask/Context.hs b/src/Futhask/Context.hs
--- a/src/Futhask/Context.hs
+++ b/src/Futhask/Context.hs
@@ -56,6 +56,7 @@
     | DefaultThreadBlockSize Int -- ^GPU backends
     | DefaultGridSize Int -- ^GPU backends
     | DefaultTileSize Int -- ^GPU backends
+    | DefaultNumGroups Int -- ^GPU backends
     | Platform String -- ^OpenCL
     | BuildOptions [String] -- ^OpenCL
     | NvrtcOptions [String] -- ^Cuda
@@ -94,6 +95,7 @@
     setDefaultThreadBlockSize :: Ptr (RawConfig c) -> Int -> IO ()
     setDefaultGridSize    :: Ptr (RawConfig c) -> Int -> IO ()
     setDefaultTileSize    :: Ptr (RawConfig c) -> Int -> IO ()
+    setDefaultNumGroups   :: Ptr (RawConfig c) -> Int -> IO ()
     -- OpenCL options
     setPlatform    :: Ptr (RawConfig c) -> CString -> IO ()
     --setLoadBinary  :: Ptr (RawConfig c) -> CString -> IO ()
@@ -120,9 +122,10 @@
     Log i     -> nofin $ setLog     config i
     Profile i -> nofin $ setProfile config i
     Device s -> nofin $ withCString s (setDevice config)
-    DefaultThreadBlockSize s -> nofin $ setDefaultThreadBlockSize config s
-    DefaultGridSize s        -> nofin $ setDefaultGridSize        config s
-    DefaultTileSize s        -> nofin $ setDefaultTileSize        config s
+    DefaultThreadBlockSize s  -> nofin $ setDefaultThreadBlockSize config s
+    DefaultGridSize s         -> nofin $ setDefaultGridSize        config s
+    DefaultTileSize s         -> nofin $ setDefaultTileSize        config s
+    DefaultNumGroups s        -> nofin $ setDefaultNumGroups       config s
     Platform p    -> nofin $ withCString p  (setPlatform   config)
     BuildOptions os -> nofin $ mapM_ (\o -> withCString o (setBuildOption config)) os
     NvrtcOptions os -> nofin $ mapM_ (\o -> withCString o (setNvrtcOption config)) os