diff --git a/cabal-install/src/Distribution/Client/ProjectConfig.hs b/cabal-install/src/Distribution/Client/ProjectConfig.hs
index 25c28950f48..56f747ac2e2 100644
--- a/cabal-install/src/Distribution/Client/ProjectConfig.hs
+++ b/cabal-install/src/Distribution/Client/ProjectConfig.hs
@@ -762,7 +762,7 @@ readProjectFileSkeleton
       readExtensionFile =
         reportParseResult verbosity extensionDescription extensionFile
           =<< parseProjectSkeleton distDownloadSrcDirectory httpTransport verbosity [] extensionFile
-          =<< (fmap (0,) $ BS.readFile extensionFile)
+          =<< fmap (0,) (BS.readFile extensionFile)
 
 -- | Render the 'ProjectConfig' format.
 --