diff --git a/git-p4.py b/git-p4.py
index c7170c9ae6..68f9f4fdc6 100755
--- a/git-p4.py
+++ b/git-p4.py
@@ -2641,6 +2641,7 @@ class P4Sync(Command, P4UserMap):
     def checkpoint(self):
         self.gitStream.write("checkpoint\n\n")
         self.gitStream.write("progress checkpoint\n\n")
+        self.gitStream.flush()
         out = self.gitOutput.readline()
         if self.verbose:
             print("checkpoint finished: " + out)