diff --git a/tools/task_kill.py b/tools/task_kill.py
index b77d78958aa..ec6b574b607 100755
--- a/tools/task_kill.py
+++ b/tools/task_kill.py
@@ -50,7 +50,7 @@ def GetOptions():
 def GetPidsPosix(process_name):
   # This is to have only one posix command, on linux we could just do:
   # pidof process_name
-  cmd = 'ps -e -o pid=,comm='
+  cmd = 'ps -e -o pid= -o comm='
   # Sample output:
   # 1 /sbin/launchd
   # 80943 /Applications/Safari.app/Contents/MacOS/Safari