diff --git a/gf.cabal b/gf.cabal
index 21093ae0b..a0b0c01dd 100644
--- a/gf.cabal
+++ b/gf.cabal
@@ -347,7 +347,7 @@ library
   else
     build-depends:
       terminfo >=0.4.0 && < 0.5,
-      unix >= 2.7.2 && < 2.8
+      unix >= 2.8
 
   if impl(ghc>=8.2)
     ghc-options: -fhide-source-paths
diff --git a/src/server/CGIUtils.hs b/src/server/CGIUtils.hs
index 3c5ce2274..b593a2b07 100644
--- a/src/server/CGIUtils.hs
+++ b/src/server/CGIUtils.hs
@@ -34,8 +34,8 @@ stderrToFile :: FilePath -> IO ()
 stderrToFile file =
     do let mode = ownerReadMode<>ownerWriteMode<>groupReadMode<>otherReadMode
            (<>) = unionFileModes
-           flags = defaultFileFlags { append = True }
-       fileFd <- openFd file WriteOnly (Just mode) flags
+           flags = defaultFileFlags { append = True, creat = Just mode }
+       fileFd <- openFd file WriteOnly flags
        dupTo fileFd stdError
        return ()
 #else