diff --git a/src/engine/join-filter.js b/src/engine/join-filter.js
index 99475666..e71ca35e 100644
--- a/src/engine/join-filter.js
+++ b/src/engine/join-filter.js
@@ -1,4 +1,4 @@
-import { singleRowLookup } from './join/lookup';
+import { rowLookup } from './join/lookup';
 import BitSet from '../table/bit-set';
 import isArray from '../util/is-array';
 
@@ -18,7 +18,7 @@ export default function(tableL, tableR, predicate, options = {}) {
 
 function hashSemiJoin(filter, tableL, tableR, [keyL, keyR]) {
   // build lookup table
-  const lut = singleRowLookup(tableR, keyR);
+  const lut = rowLookup(tableR, keyR);
 
   // scan table, update filter with matches
   tableL.scan((rowL, data) => {
diff --git a/src/engine/join.js b/src/engine/join.js
index ea68d274..e242402f 100644
--- a/src/engine/join.js
+++ b/src/engine/join.js
@@ -1,4 +1,4 @@
-import { multiRowLookup } from './join/lookup';
+import { indexLookup } from './join/lookup';
 import columnSet from '../table/column-set';
 import concat from '../util/concat';
 import isArray from '../util/is-array';
@@ -90,7 +90,7 @@ function hashJoin(emit, [keyL, keyR], dataL, dataR, idxL, idxR, hitL, hitR, nL,
   }
 
   // build lookup table
-  const lut = multiRowLookup(idxHash, dataHash, keyHash);
+  const lut = indexLookup(idxHash, dataHash, keyHash);
 
   // scan other table
   const m = idxScan.length;
diff --git a/src/engine/join/lookup.js b/src/engine/join/lookup.js
index 0dbbada8..745a4be0 100644
--- a/src/engine/join/lookup.js
+++ b/src/engine/join/lookup.js
@@ -1,4 +1,4 @@
-export function singleRowLookup(table, hash) {
+export function rowLookup(table, hash) {
   const lut = new Map();
   table.scan((row, data) => {
     const key = hash(row, data);
@@ -9,7 +9,7 @@ export function singleRowLookup(table, hash) {
   return lut;
 }
 
-export function multiRowLookup(idx, data, hash) {
+export function indexLookup(idx, data, hash) {
   const lut = new Map();
   const n = idx.length;
   for (let i = 0; i < n; ++i) {
@@ -17,8 +17,8 @@ export function multiRowLookup(idx, data, hash) {
     const key = hash(row, data);
     if (key != null && key === key) {
       lut.has(key)
-        ? lut.get(key).push(row)
-        : lut.set(key, [row]);
+        ? lut.get(key).push(i)
+        : lut.set(key, [i]);
     }
   }
   return lut;
diff --git a/src/engine/lookup.js b/src/engine/lookup.js
index 519baf1e..ee435580 100644
--- a/src/engine/lookup.js
+++ b/src/engine/lookup.js
@@ -1,4 +1,4 @@
-import { singleRowLookup } from './join/lookup';
+import { rowLookup } from './join/lookup';
 import { aggregateGet } from './reduce/util';
 import columnSet from '../table/column-set';
 import NULL from '../util/null';
@@ -12,7 +12,7 @@ export default function(tableL, tableR, [keyL, keyR], { names, exprs, ops }) {
   names.forEach(name => cols.add(name, Array(total).fill(NULL)));
 
   // build lookup table
-  const lut = singleRowLookup(tableR, keyR);
+  const lut = rowLookup(tableR, keyR);
 
   // generate setter function for lookup match
   const set = unroll(
diff --git a/test/verbs/join-test.js b/test/verbs/join-test.js
index ad12a88e..c8d7109b 100644
--- a/test/verbs/join-test.js
+++ b/test/verbs/join-test.js
@@ -124,7 +124,25 @@ tape('join handles filtered tables', t => {
     key: [ 1, 2, 5 ],
     value1: [ 1, 2, undefined ],
     value2: [ 1, 2, 5 ]
-  }, 'natural left join on filtered data');
+  }, 'natural right join on filtered data');
+
+  const dt = table({
+    year:  [2017, 2017, 2017, 2018, 2018, 2018],
+    month: ['01', '02', 'YR', '01', '02', 'YR'],
+    count: [6074, 7135, 220582, 5761, 6764, 222153]
+  });
+
+  const jt = dt
+    .filter(d => d.month === 'YR')
+    .select('year', {count: 'total'})
+    .join(dt.filter(d => d.month !== 'YR'));
+
+  tableEqual(t, jt, {
+    total: [ 220582, 220582, 222153, 222153 ],
+    year: [ 2017, 2017, 2018, 2018 ],
+    month: [ '01', '02', '01', '02' ],
+    count: [ 6074, 7135, 5761, 6764 ]
+  }, 'join of two filtered tables');
 
   t.end();
 });