diff --git a/lib/msf/base/sessions/command_shell.rb b/lib/msf/base/sessions/command_shell.rb
index 5bed8c0bdc..1ec9a292f2 100644
--- a/lib/msf/base/sessions/command_shell.rb
+++ b/lib/msf/base/sessions/command_shell.rb
@@ -204,6 +204,8 @@ class CommandShell
 	# Writes to the command shell.
 	#
 	def shell_write(buf)
+		return if not buf
+
 		begin
 			framework.events.on_session_command(self, buf.strip)
 			rstream.write(buf)