diff --git a/scripts/sanityTest.pl b/scripts/sanityTest.pl
index 015b5a78fe7594eb50131d64b637ac076b0f74f6..65cd5a95ec20de13b552c749ae0e2c4be2ab9011 100644
--- a/scripts/sanityTest.pl
+++ b/scripts/sanityTest.pl
@@ -72,6 +72,9 @@
 
 $os     = $ARGV[0];
 
+# flush output
+$| = 1;
+
 if (lc($os) eq "win") {
     $pathsep = "\\";
 }