diff --git a/tools/testing/ktest/ktest.pl b/tools/testing/ktest/ktest.pl
index f20a81bb3abe2..e90e2e7cb72cf 100755
--- a/tools/testing/ktest/ktest.pl
+++ b/tools/testing/ktest/ktest.pl
@@ -11,6 +11,7 @@
 use File::Copy qw(cp);
 use FileHandle;
 use FindBin;
+use IO::Handle;
 
 my $VERSION = "0.2";
 
@@ -4091,6 +4092,7 @@ sub make_warnings_file {
 	unlink $opt{"LOG_FILE"};
     }
     open(LOG, ">> $opt{LOG_FILE}") or die "Can't write to $opt{LOG_FILE}";
+    LOG->autoflush(1);
 }
 
 doprint "\n\nSTARTING AUTOMATED TESTS\n\n";