diff --git a/compiler/custom_error.py b/compiler/custom_error.py
index c94643310..eedb6f738 100644
--- a/compiler/custom_error.py
+++ b/compiler/custom_error.py
@@ -2,7 +2,4 @@ class UnparallelizableError(Exception):
     pass
 
 class AdjLineNotImplementedError(Exception):
-    pass
-
-class ExpansionError(RuntimeError): 
-    pass 
\ No newline at end of file
+    pass
\ No newline at end of file
diff --git a/compiler/pash_compiler.py b/compiler/pash_compiler.py
index 4992740a4..080681d88 100644
--- a/compiler/pash_compiler.py
+++ b/compiler/pash_compiler.py
@@ -4,6 +4,7 @@
 from datetime import datetime
 
 from sh_expand import env_vars_util
+from sh_expand import ExpansionError 
 
 import config
 from ir import *