diff --git a/src/Pact/Types/Util.hs b/src/Pact/Types/Util.hs
index acb46420e..4c120a01a 100644
--- a/src/Pact/Types/Util.hs
+++ b/src/Pact/Types/Util.hs
@@ -348,6 +348,9 @@ base64DowngradeErrorMessage
 base64DowngradeErrorMessage
   (L.stripPrefix "invalid padding at offset: " -> Just suffix) =
       "invalid padding near offset " <> suffix
+base64DowngradeErrorMessage
+  (L.stripPrefix "invalid padding near offset " -> Just suffix) =
+      "SANITY CHECK " <> suffix
 base64DowngradeErrorMessage
   "Base64-encoded bytestring has invalid size" =
       "invalid base64 encoding near offset 0"