diff --git a/lib/jwt/__init__.py b/lib/jwt/__init__.py
index 9d4b6744..457a4e35 100644
--- a/lib/jwt/__init__.py
+++ b/lib/jwt/__init__.py
@@ -27,7 +27,7 @@ from .exceptions import (
 )
 from .jwks_client import PyJWKClient
 
-__version__ = "2.10.0"
+__version__ = "2.10.1"
 
 __title__ = "PyJWT"
 __description__ = "JSON Web Token implementation in Python"
diff --git a/lib/jwt/api_jwt.py b/lib/jwt/api_jwt.py
index fa4d5e6f..3a201436 100644
--- a/lib/jwt/api_jwt.py
+++ b/lib/jwt/api_jwt.py
@@ -419,11 +419,11 @@ class PyJWT:
         if "iss" not in payload:
             raise MissingRequiredClaimError("iss")
 
-        if isinstance(issuer, Sequence):
-            if payload["iss"] not in issuer:
+        if isinstance(issuer, str):
+            if payload["iss"] != issuer:
                 raise InvalidIssuerError("Invalid issuer")
         else:
-            if payload["iss"] != issuer:
+            if payload["iss"] not in issuer:
                 raise InvalidIssuerError("Invalid issuer")