diff --git a/src/clean/getPositionsForAutoValue.ts b/src/clean/getPositionsForAutoValue.ts
index 31aaefb..b98b01d 100644
--- a/src/clean/getPositionsForAutoValue.ts
+++ b/src/clean/getPositionsForAutoValue.ts
@@ -5,6 +5,7 @@ import { getLastPartOfKey, getParentOfKey } from '../utility/index.js'
 interface GetPositionsForAutoValueProps {
   fieldName: string
   isModifier?: boolean
+  isUpsert?: boolean
   mongoObject: MongoObject
 }
 
@@ -42,6 +43,7 @@ interface PositionInfo {
 export default function getPositionsForAutoValue ({
   fieldName,
   isModifier,
+  isUpsert,
   mongoObject
 }: GetPositionsForAutoValueProps): PositionInfo[] {
   // Positions for this field
@@ -130,5 +132,17 @@ export default function getPositionsForAutoValue ({
     })
   }
 
+  // If we made it this far, we still want to call the autoValue
+  // function once for the field, so we'll add a would-be position for it.
+  if (positions.length === 0 && isModifier === true && isUpsert !== true) {
+    positions.push({
+      key: fieldName,
+      // @ts-expect-error incorrect type in mongo-object package
+      value: undefined,
+      operator: '$set',
+      position: `$set[${fieldName}]`
+    })
+  }
+
   return positions
 }
diff --git a/src/clean/setAutoValues.ts b/src/clean/setAutoValues.ts
index 8b1c33a..c01efa9 100755
--- a/src/clean/setAutoValues.ts
+++ b/src/clean/setAutoValues.ts
@@ -69,6 +69,7 @@ function setAutoValues (
       const positions = getPositionsForAutoValue({
         fieldName,
         isModifier,
+        isUpsert,
         mongoObject
       })
 
diff --git a/test/SimpleSchema_autoValueFunctions.tests.ts b/test/SimpleSchema_autoValueFunctions.tests.ts
index 9729022..1dca55d 100644
--- a/test/SimpleSchema_autoValueFunctions.tests.ts
+++ b/test/SimpleSchema_autoValueFunctions.tests.ts
@@ -153,4 +153,40 @@ describe('SimpleSchema - autoValueFunctions', function () {
     expect(autoValueFunctions[1].fieldName).toBe('a.b.$.z')
     expect(autoValueFunctions[1].closestSubschemaFieldName).toBe('a.b.$')
   })
+
+  it('modifier with autovalue in subschema', function () {
+    const datesSchema = new SimpleSchema({
+      updatedAt: {
+        type: Date,
+        label: 'Updated At',
+        optional: true,
+        autoValue: function () {
+          return new Date()
+        }
+      }
+    })
+
+    const schema = new SimpleSchema({
+      otherStuff: {
+        type: String,
+        optional: true
+      },
+      dates: {
+        type: datesSchema,
+        label: 'Dates',
+        optional: true,
+        defaultValue: {}
+      }
+    })
+
+    const modifier = {
+      $set: { otherStuff: 'someOtherString' }
+    }
+
+    const cleanedModifier = schema.clean(modifier, {
+      isModifier: true
+    }) as any
+    expect(cleanedModifier.$set['dates.updatedAt']).not.toBeUndefined()
+    expect(cleanedModifier.$set['dates.updatedAt']).toBeInstanceOf(Date)
+  })
 })