diff --git a/bip-0138.md b/bip-0138.md
index d339bedf..2cefbe12 100644
--- a/bip-0138.md
+++ b/bip-0138.md
@@ -338,7 +338,7 @@ CHACHA20_POLY1305 (per RFC 8439) supports plaintext up to 2^38 - 64 bytes.
 Implementations MAY impose stricter limits based on platform constraints
 (e.g., limiting to 2^32 - 1 bytes on 32-bit architectures).
 
-Implementations MUST reject empty payloads.
+Implementations MUST reject empty payloads (i.e. zero content items).
 
 #### Ciphertext
 
diff --git a/bip-0138/test_vectors/payload.json b/bip-0138/test_vectors/payload.json
index 826c5145..90ee8f65 100644
--- a/bip-0138/test_vectors/payload.json
+++ b/bip-0138/test_vectors/payload.json
@@ -9,5 +9,10 @@
         "content": "61"
       }
     ]
+  },
+  {
+    "description": "Payload with no content item.",
+    "valid": false,
+    "payload": "00"
   }
 ]