diff --git a/cryptography/exceptions.py b/cryptography/exceptions.py
index 44363c2..2654b45 100644
--- a/cryptography/exceptions.py
+++ b/cryptography/exceptions.py
@@ -34,3 +34,7 @@
 
 class InvalidSignature(Exception):
     pass
+
+
+class InternalError(Exception):
+    pass