diff --git a/test/py/u_boot_spawn.py b/test/py/u_boot_spawn.py
index a5f4a8e91baed1aa8c9f3dce7c0072fc28ca13da..d15517389e510fa8ddd7d96cfa5dd4b73f86e285 100644
--- a/test/py/u_boot_spawn.py
+++ b/test/py/u_boot_spawn.py
@@ -38,6 +38,11 @@ class Spawn(object):
         self.before = ''
         self.after = ''
         self.timeout = None
+        # http://stackoverflow.com/questions/7857352/python-regex-to-match-vt100-escape-sequences
+        # Note that re.I doesn't seem to work with this regex (or perhaps the
+        # version of Python in Ubuntu 14.04), hence the inclusion of a-z inside
+        # [] instead.
+        self.re_vt100 = re.compile('(\x1b\[|\x9b)[^@-_a-z]*[@-_a-z]|\x1b[@-_a-z]')
 
         (self.pid, self.fd) = pty.fork()
         if self.pid == 0:
@@ -168,6 +173,10 @@ class Spawn(object):
                 if self.logfile_read:
                     self.logfile_read.write(c)
                 self.buf += c
+                # count=0 is supposed to be the default, which indicates
+                # unlimited substitutions, but in practice the version of
+                # Python in Ubuntu 14.04 appears to default to count=2!
+                self.buf = self.re_vt100.sub('', self.buf, count=1000000)
         finally:
             if self.logfile_read:
                 self.logfile_read.flush()