diff --git a/zip-0317.html b/zip-0317.html
index 05c05320..1d6ef4d1 100644
--- a/zip-0317.html
+++ b/zip-0317.html
@@ -281,7 +281,7 @@ Pull-Request: &lt;<a href="https://github.com/zcash/zips/pull/631">https://githu
                         <li>For each transaction
                             <span class="math">\(tx\)</span>
                          in the mempool, calculate
-                            <span class="math">\(tx.\!weight\_ratio = \mathsf{min}\!\left(\frac{tx.fee}{conventional\_fee(tx)},\, weight\_ratio\_cap\right)\!\)</span>
+                            <span class="math">\(tx.\!weight\_ratio = \mathsf{min}\!\left(\frac{\mathsf{max}(1,\, tx.fee)}{conventional\_fee(tx)},\, weight\_ratio\_cap\right)\!\)</span>
                          and add the transaction to the set of candidate transactions.</li>
                         <li>Repeat while there is any candidate transaction that pays at least the conventional fee:
                             <ol type="a">
diff --git a/zip-0317.rst b/zip-0317.rst
index 9baaae61..36363446 100644
--- a/zip-0317.rst
+++ b/zip-0317.rst
@@ -276,7 +276,7 @@ The following algorithm is RECOMMENDED for constructing block templates
 from a set of transactions in a node's mempool:
 
 1. For each transaction :math:`tx` in the mempool, calculate
-   :math:`tx.\!weight\_ratio = \mathsf{min}\!\left(\frac{tx.fee}{conventional\_fee(tx)},\, weight\_ratio\_cap\right)\!`
+   :math:`tx.\!weight\_ratio = \mathsf{min}\!\left(\frac{\mathsf{max}(1,\, tx.fee)}{conventional\_fee(tx)},\, weight\_ratio\_cap\right)\!`
    and add the transaction to the set of candidate transactions.
 
 2. Repeat while there is any candidate transaction that pays at least the