diff --git a/hls-plugin-api.cabal b/hls-plugin-api.cabal
--- a/hls-plugin-api.cabal
+++ b/hls-plugin-api.cabal
@@ -1,6 +1,6 @@
 cabal-version: 2.4
 name:          hls-plugin-api
-version:       1.1.0.1
+version:       1.1.0.2
 synopsis:      Haskell Language Server API for plugin communication
 description:
   Please see the README on GitHub at <https://github.com/haskell/haskell-language-server#readme>
@@ -43,6 +43,8 @@
     , dependent-sum
     , Diff                  ^>=0.4.0
     , dlist
+    , ghc
+    , ghc-api-compat
     , hashable
     , hslogger
     , lens
@@ -50,7 +52,7 @@
     , opentelemetry
     , process
     , regex-tdfa            >=1.3.1.0
-    , hls-graph             ^>=1.3
+    , hls-graph             ^>=1.4
     , text
     , unordered-containers
 
diff --git a/src/Ide/Plugin/ConfigUtils.hs b/src/Ide/Plugin/ConfigUtils.hs
--- a/src/Ide/Plugin/ConfigUtils.hs
+++ b/src/Ide/Plugin/ConfigUtils.hs
@@ -22,7 +22,7 @@
 -- since diagnostics emit in arbitrary shake rules -- we don't know
 -- whether a plugin is capable of producing diagnostics.
 
--- | Generates a defalut 'Config', but remains only effective items
+-- | Generates a default 'Config', but remains only effective items
 pluginsToDefaultConfig :: IdePlugins a -> A.Value
 pluginsToDefaultConfig IdePlugins {..} =
   A.Object $
diff --git a/src/Ide/Plugin/Properties.hs b/src/Ide/Plugin/Properties.hs
--- a/src/Ide/Plugin/Properties.hs
+++ b/src/Ide/Plugin/Properties.hs
@@ -48,7 +48,7 @@
 import           Data.Function        ((&))
 import           Data.Kind            (Constraint, Type)
 import qualified Data.Map.Strict      as Map
-import           Data.Proxy (Proxy (..))
+import           Data.Proxy           (Proxy (..))
 import qualified Data.Text            as T
 import           GHC.OverloadedLabels (IsLabel (..))
 import           GHC.TypeLits
diff --git a/src/Ide/Types.hs b/src/Ide/Types.hs
--- a/src/Ide/Types.hs
+++ b/src/Ide/Types.hs
@@ -39,6 +39,7 @@
 import qualified Data.Text                       as T
 import           Data.Text.Encoding              (encodeUtf8)
 import           Development.IDE.Graph
+import           DynFlags                        (DynFlags)
 import           GHC.Generics
 import           Ide.Plugin.Config
 import           Ide.Plugin.Properties
@@ -56,6 +57,30 @@
 newtype IdePlugins ideState = IdePlugins
   { ipMap :: [(PluginId, PluginDescriptor ideState)]}
 
+-- | Hooks for modifying the 'DynFlags' at different times of the compilation
+-- process. Plugins can install a 'DynFlagsModifications' via
+-- 'pluginModifyDynflags' in their 'PluginDescriptor'.
+data DynFlagsModifications =
+  DynFlagsModifications
+    { -- | Invoked immediately at the package level. Changes to the 'DynFlags'
+      -- made in 'dynFlagsModifyGlobal' are guaranteed to be seen everywhere in
+      -- the compilation pipeline.
+      dynFlagsModifyGlobal :: DynFlags -> DynFlags
+      -- | Invoked just before the parsing step, and reset immediately
+      -- afterwards. 'dynFlagsModifyParser' allows plugins to enable language
+      -- extensions only during parsing. for example, to let them enable
+      -- certain pieces of syntax.
+    , dynFlagsModifyParser :: DynFlags -> DynFlags
+    }
+
+instance Semigroup DynFlagsModifications where
+  DynFlagsModifications g1 p1 <> DynFlagsModifications g2 p2 =
+    DynFlagsModifications (g2 . g1) (p2 . p1)
+
+instance Monoid DynFlagsModifications where
+  mempty = DynFlagsModifications id id
+
+
 -- ---------------------------------------------------------------------
 
 data PluginDescriptor ideState =
@@ -65,6 +90,7 @@
                    , pluginHandlers     :: PluginHandlers ideState
                    , pluginConfigDescriptor :: ConfigDescriptor
                    , pluginNotificationHandlers :: PluginNotificationHandlers ideState
+                   , pluginModifyDynflags :: DynFlagsModifications
                    }
 
 -- | An existential wrapper of 'Properties'
@@ -296,6 +322,7 @@
     mempty
     mempty
     defaultConfigDescriptor
+    mempty
     mempty
 
 newtype CommandId = CommandId T.Text