diff --git a/.flake8 b/.flake8
index fab72cf..58d33b8 100644
--- a/.flake8
+++ b/.flake8
@@ -1,5 +1,5 @@
 [flake8]
-max-line-length = 88
+max-line-length = 80
 extend-select = B950
 extend-ignore = E203,E501,E701
 
diff --git a/bfxapi/_client.py b/bfxapi/_client.py
index 21f2f86..f8fc67c 100644
--- a/bfxapi/_client.py
+++ b/bfxapi/_client.py
@@ -37,11 +37,11 @@ class Client:
             }
         elif api_key:
             raise IncompleteCredentialError(
-                "You must provide both an API-KEY and an API-SECRET (missing API-KEY)."
+                "You must provide both API-KEY and API-SECRET (missing API-KEY)."
             )
         elif api_secret:
             raise IncompleteCredentialError(
-                "You must provide both an API-KEY and an API-SECRET (missing API-SECRET)."
+                "You must provide both API-KEY and API-SECRET (missing API-SECRET)."
             )
 
         self.rest = BfxRestInterface(rest_host, api_key, api_secret)
diff --git a/bfxapi/rest/middleware/middleware.py b/bfxapi/rest/middleware/middleware.py
index 7047127..48a4da4 100644
--- a/bfxapi/rest/middleware/middleware.py
+++ b/bfxapi/rest/middleware/middleware.py
@@ -35,7 +35,7 @@ class Middleware:
     def __build_authentication_headers(self, endpoint: str, data: Optional[str] = None):
         assert isinstance(self.api_key, str) and isinstance(
             self.api_secret, str
-        ), "API_KEY and API_SECRET must be both str to call __build_authentication_headers"
+        ), "API_KEY and API_SECRET must be both strings"
 
         nonce = str(round(time.time() * 1_000_000))