diff --git a/test/types/schema.test.ts b/test/types/schema.test.ts
index 2ab4698e4b..b0e148afce 100644
--- a/test/types/schema.test.ts
+++ b/test/types/schema.test.ts
@@ -872,3 +872,28 @@ function gh12431() {
   type Example = InferSchemaType<typeof testSchema>;
   expectType<{ testDate?: Date, testDecimal?: Types.Decimal128 }>({} as Example);
 }
+
+function gh12562() {
+  const emailRegExp = /@/;
+  const userSchema = new Schema(
+    {
+      email: {
+        type: String,
+        trim: true,
+        validate: {
+          validator: (value: string) => emailRegExp.test(value),
+          message: 'Email is not valid'
+        },
+        index: { // uncomment the index object and for me trim was throwing an error
+          partialFilterExpression: {
+            email: {
+              $exists: true,
+              $ne: null
+            }
+          }
+        },
+        select: false
+      }
+    }
+  );
+}
diff --git a/types/schematypes.d.ts b/types/schematypes.d.ts
index 899660d9fe..093651d140 100644
--- a/types/schematypes.d.ts
+++ b/types/schematypes.d.ts
@@ -100,7 +100,7 @@ declare module 'mongoose' {
      * If [truthy](https://masteringjs.io/tutorials/fundamentals/truthy), Mongoose will
      * build an index on this path when the model is compiled.
      */
-    index?: boolean | IndexDirection;
+    index?: boolean | IndexDirection | IndexOptions;
 
     /**
      * If [truthy](https://masteringjs.io/tutorials/fundamentals/truthy), Mongoose