diff --git a/test/testrunner/testrunner.py b/test/testrunner/testrunner.py
index 0b9a6e6..e6376ef 100755
--- a/test/testrunner/testrunner.py
+++ b/test/testrunner/testrunner.py
@@ -260,6 +260,16 @@
   global semaphore
   semaphore = threading.Semaphore(n_thread)
 
+  if not sys.stdout.isatty():
+    global COLOR_ERROR
+    global COLOR_PASS
+    global COLOR_SKIP
+    global COLOR_NORMAL
+    COLOR_ERROR = ''
+    COLOR_PASS = ''
+    COLOR_SKIP = ''
+    COLOR_NORMAL = ''
+
 
 def run_tests(tests):
   """Creates thread workers to run the tests.
@@ -895,6 +905,7 @@
     if options['gdb_arg']:
       gdb_arg = options['gdb_arg']
   timeout = options['timeout']
+
   return test
 
 def main():