diff --git a/postgresql-libpq.cabal b/postgresql-libpq.cabal
index 66ffe8f..e7ec426 100644
--- a/postgresql-libpq.cabal
+++ b/postgresql-libpq.cabal
@@ -45,7 +45,7 @@ custom-setup
 
 -- If true,  use pkg-config,  otherwise use the pg_config based build
 -- configuration
-flag use-pkg-config
+Flag use-pkg-config
   default: False
   manual:  True