diff --git a/include/token_authorization_middleware.hpp b/include/token_authorization_middleware.hpp
index 7e4e3bb..e9eb65f 100644
--- a/include/token_authorization_middleware.hpp
+++ b/include/token_authorization_middleware.hpp
@@ -223,8 +223,14 @@
             {
                 return nullptr;
             }
+
+            if (csrf.size() != crow::persistent_data::sessionTokenSize)
+            {
+                return nullptr;
+            }
             // Reject if csrf token not available
-            if (csrf != session->csrfToken)
+            if (!crow::utility::constantTimeStringCompare(csrf,
+                                                          session->csrfToken))
             {
                 return nullptr;
             }