diff --git a/modules/exploits/windows/winrm/winrm_powershell.rb b/modules/exploits/windows/winrm/winrm_powershell.rb
index 2b5d0312e2..dbb0fffdef 100644
--- a/modules/exploits/windows/winrm/winrm_powershell.rb
+++ b/modules/exploits/windows/winrm/winrm_powershell.rb
@@ -67,7 +67,7 @@ class Metasploit3 < Msf::Exploit::Remote
 		if streams['stdout'].include? 'Unrestricted'
 			return Msf::Exploit::CheckCode::Vulnerable
 		else
-			unless streams['stderr'] = ''
+			unless streams['stderr'] == ''
 				print_error streams['stderr']
 			end
 			return Msf::Exploit::CheckCode::Safe