diff --git a/specs/architecture.html b/specs/architecture.html
index 5d692df3..21976a72 100644
--- a/specs/architecture.html
+++ b/specs/architecture.html
@@ -367,7 +367,7 @@ <h2>Relationship to Previous Concepts</h2>
       	  <tr>
       	    <td>Payment App</td>
       	    <td>Digital Wallet, Payment Instrument </td>
-      	    <td>A piece of software to pay</td>
+      	    <td>An application, registered by the payer, that supports processing payment requests and returning payment responses for one or more payment methods.</td>
       	  </tr>
       	  <tr>
       	    <td>Payment Method</td>