diff --git a/Lib/unittest.py b/Lib/unittest.py
index 742871b..5beeb05 100644
--- a/Lib/unittest.py
+++ b/Lib/unittest.py
@@ -679,6 +679,7 @@
         if self.showAll:
             self.stream.write(self.getDescription(test))
             self.stream.write(" ... ")
+            self.stream.flush()
 
     def addSuccess(self, test):
         TestResult.addSuccess(self, test)
@@ -686,6 +687,7 @@
             self.stream.writeln("ok")
         elif self.dots:
             self.stream.write('.')
+            self.stream.flush()
 
     def addError(self, test, err):
         TestResult.addError(self, test, err)
@@ -693,6 +695,7 @@
             self.stream.writeln("ERROR")
         elif self.dots:
             self.stream.write('E')
+            self.stream.flush()
 
     def addFailure(self, test, err):
         TestResult.addFailure(self, test, err)
@@ -700,6 +703,7 @@
             self.stream.writeln("FAIL")
         elif self.dots:
             self.stream.write('F')
+            self.stream.flush()
 
     def printErrors(self):
         if self.dots or self.showAll: