diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c
index 56cc7fea4f52756fdbfd01c50af729872561d7a9..9776df270a9482c7fc96406d2727fd8506d0745c 100644
--- a/src/test/isolation/isolationtester.c
+++ b/src/test/isolation/isolationtester.c
@@ -70,6 +70,8 @@ exit_nicely(void)
 
 	for (i = 0; i < nconns; i++)
 		PQfinish(conns[i]);
+	fflush(stderr);
+	fflush(stdout);
 	exit(1);
 }
 
@@ -283,6 +285,8 @@ main(int argc, char **argv)
 	/* Clean up and exit */
 	for (i = 0; i < nconns; i++)
 		PQfinish(conns[i]);
+	fflush(stderr);
+	fflush(stdout);
 	return 0;
 }