diff --git a/salt/grains/core.py b/salt/grains/core.py
index e1f0390205d..22fc1b6d6f7 100644
--- a/salt/grains/core.py
+++ b/salt/grains/core.py
@@ -2552,7 +2552,7 @@ def _windows_wwns():
     '''
     Return Fibre Channel port WWNs from a Windows host.
     '''
-    ps_cmd = r'Get-WmiObject -class MSFC_FibrePortHBAAttributes -namespace "root\WMI" | Select -Expandproperty Attributes | %{($_.PortWWN | % {"{0:x2}" -f $_}) -join ""}'
+    ps_cmd = r'Get-WmiObject -ErrorAction Stop -class MSFC_FibrePortHBAAttributes -namespace "root\WMI" | Select -Expandproperty Attributes | %{($_.PortWWN | % {"{0:x2}" -f $_}) -join ""}'
 
     ret = []
 
diff --git a/salt/modules/cmdmod.py b/salt/modules/cmdmod.py
index bc4678346c8..bcf7587940d 100644
--- a/salt/modules/cmdmod.py
+++ b/salt/modules/cmdmod.py
@@ -3241,6 +3241,13 @@ def powershell(cmd,
     else:
         encoded_cmd = False
 
+    # Put the whole command inside a try / catch block
+    # Some errors in PowerShell are not "Terminating Errors" and will not be
+    # caught in a try/catch block. For example, the `Get-WmiObject` command will
+    # often return a "Non Terminating Error". To fix this, make sure
+    # `-ErrorAction Stop` is set in the powershell command
+    cmd = 'try {' + cmd + '} catch { "{}" | ConvertTo-JSON}'
+
     # Retrieve the response, while overriding shell with 'powershell'
     response = run(cmd,
                    cwd=cwd,