diff --git a/web/src/test/auto/headless/engine/predictive-text/worker-thread/context/context-tokenization.tests.ts b/web/src/test/auto/headless/engine/predictive-text/worker-thread/context/context-tokenization.tests.ts
index 0729257af9..971f11e537 100644
--- a/web/src/test/auto/headless/engine/predictive-text/worker-thread/context/context-tokenization.tests.ts
+++ b/web/src/test/auto/headless/engine/predictive-text/worker-thread/context/context-tokenization.tests.ts
@@ -1635,13 +1635,13 @@ describe('ContextTokenization', function() {
       expectedMap.set(0, { insert: 't', deleteLeft: 0 });
       assert.equal(results.tokenizedTransform.size, 1);
       assert.deepEqual(results.tokenizedTransform, expectedMap);
-      assert.equal(results.alignment.edgeWindow.sliceIndex, 4);
       assert.deepEqual(results.alignment.merges, [
         {
           inputs: [
-            { text: 'can', index: 2 /* + 4 */ },
-            { text: '\'',  index: 3 /* + 4 */ }
-          ], match: { text: 'can\'t', index: 2 /* + 4 */}
+            // The `index` values here are pre-offset from the edge window's .sliceIndex.
+            { text: 'can', index: 6 - results.alignment.edgeWindow.sliceIndex },
+            { text: '\'',  index: 7 - results.alignment.edgeWindow.sliceIndex }
+          ], match: { text: 'can\'t', index: 6 - results.alignment.edgeWindow.sliceIndex }
         }
       ]);
       assert.deepEqual(results.alignment.splits, []);
@@ -1669,14 +1669,13 @@ describe('ContextTokenization', function() {
       expectedMap.set(2, { insert: '', deleteLeft: 0 });
       assert.equal(results.tokenizedTransform.size, 2);
       assert.deepEqual(results.tokenizedTransform, expectedMap);
-      assert.equal(results.alignment.edgeWindow.sliceIndex, 4);
       assert.deepEqual(results.alignment.merges, []);
       assert.deepEqual(results.alignment.splits, [
         {
-          input: { text: 'can\'', index: 2 /* + 4 */},
+          input: { text: 'can\'', index: 6 - results.alignment.edgeWindow.sliceIndex},
           matches: [
-            { text: 'can', index: 2 /* + 4 */, textOffset: 0 },
-            { text: '\'',  index: 3 /* + 4 */, textOffset: 3 }
+            { text: 'can', index: 6 - results.alignment.edgeWindow.sliceIndex, textOffset: 0 },
+            { text: '\'',  index: 7 - results.alignment.edgeWindow.sliceIndex, textOffset: 3 }
           ]
         }
       ]);
@@ -1701,14 +1700,13 @@ describe('ContextTokenization', function() {
       expectedMap.set(1, { insert: '?', deleteLeft: 0 });
       assert.equal(results.tokenizedTransform.size, 1);
       assert.deepEqual(results.tokenizedTransform, expectedMap);
-      assert.equal(results.alignment.edgeWindow.sliceIndex, 4);
       assert.deepEqual(results.alignment.merges, []);
       assert.deepEqual(results.alignment.splits, [
         {
-          input: { text: 'can\'', index: 2 /* + 4 */},
+          input: { text: 'can\'', index: 6 - results.alignment.edgeWindow.sliceIndex},
           matches: [
-            { text: 'can', index: 2 /* + 4 */, textOffset: 0 },
-            { text: '\'',  index: 3 /* + 4 */, textOffset: 3 }
+            { text: 'can', index: 6 - results.alignment.edgeWindow.sliceIndex, textOffset: 0 },
+            { text: '\'',  index: 7 - results.alignment.edgeWindow.sliceIndex, textOffset: 3 }
           ]
         }
       ]);