diff --git a/cabal-validate/src/ProcessUtil.hs b/cabal-validate/src/ProcessUtil.hs
index 86c5c16e73f..7ed88774865 100644
--- a/cabal-validate/src/ProcessUtil.hs
+++ b/cabal-validate/src/ProcessUtil.hs
@@ -15,6 +15,7 @@ import qualified Data.Text.Lazy as T (toStrict)
 import qualified Data.Text.Lazy.Encoding as T (decodeUtf8)
 import System.Directory (withCurrentDirectory)
 import System.Exit (ExitCode (ExitFailure, ExitSuccess))
+import System.IO (hFlush, stdout, stderr)
 import System.Process.Typed (ExitCodeException (..), proc, readProcess, runProcess)
 
 import ANSI (SGR (BrightBlue, BrightGreen, BrightRed, Reset), setSGR)
@@ -65,6 +66,8 @@ timed opts command args = do
     if verbosity opts > Quiet
       then do
         exitCode <- runProcess process
+        hFlush stdout
+        hFlush stderr
         pure (exitCode, ByteString.empty, ByteString.empty)
       else readProcess process