Index: utils/lit/tests/Inputs/shtest-shell/redirects.txt
===================================================================
--- utils/lit/tests/Inputs/shtest-shell/redirects.txt
+++ utils/lit/tests/Inputs/shtest-shell/redirects.txt
@@ -39,3 +39,4 @@
 # COMBINED-WRITE-NOT: not-present
 # COMBINED-WRITE: a line on stdout
 # COMBINED-WRITE: a line on stderr
+
Index: utils/lit/tests/Inputs/shtest-shell/write-to-stderr.py
===================================================================
--- utils/lit/tests/Inputs/shtest-shell/write-to-stderr.py
+++ utils/lit/tests/Inputs/shtest-shell/write-to-stderr.py
@@ -1,3 +1,4 @@
 #!/usr/bin/env python
 import sys
 sys.stderr.write("a line on stderr\n")
+sys.stderr.flush()
Index: utils/lit/tests/Inputs/shtest-shell/write-to-stdout-and-stderr.py
===================================================================
--- utils/lit/tests/Inputs/shtest-shell/write-to-stdout-and-stderr.py
+++ utils/lit/tests/Inputs/shtest-shell/write-to-stdout-and-stderr.py
@@ -1,4 +1,6 @@
 #!/usr/bin/env python
 import sys
 sys.stdout.write("a line on stdout\n")
+sys.stdout.flush()
 sys.stderr.write("a line on stderr\n")
+sys.stderr.flush()