diff --git a/gprMax/exceptions.py b/gprMax/exceptions.py
index 4898efb2..67710407 100644
--- a/gprMax/exceptions.py
+++ b/gprMax/exceptions.py
@@ -17,4 +17,5 @@
 # along with gprMax.  If not, see <http://www.gnu.org/licenses/>.
 
 class CmdInputError(ValueError):
-    """Handles errors in user specified commands. Subclasses the ValueError class."""
\ No newline at end of file
+    """Handles errors in user specified commands. Subclasses the ValueError class."""
+    pass
\ No newline at end of file