diff --git a/linter.py b/linter.py
index dae1b7a..f259f22 100644
--- a/linter.py
+++ b/linter.py
@@ -5,7 +5,7 @@
 
 class Shellcheck(Linter):
 
-    cmd = 'shellcheck --format=gcc ${args} -'
+    cmd = 'shellcheck --external-sources --format=gcc ${args} -'
     if sublime.platform() == 'windows' and not which('shellcheck') and which('wsl'):
         cmd = 'wsl ' + cmd