diff --git a/packages/simple-form/src/get-form-manager.ts b/packages/simple-form/src/get-form-manager.ts
index 9ed1063..6af126a 100644
--- a/packages/simple-form/src/get-form-manager.ts
+++ b/packages/simple-form/src/get-form-manager.ts
@@ -67,7 +67,7 @@ export const getFormManager = <TFields>(formDefinition: ReturnType<typeof useFor
      * form manager can be passed on to field controls and they have access to the form state.
      */
     formState,
-    /** This is the `isSubitting` parameter you called this hook with. It is included in the result so the
+    /** This is the `isSubmitting` parameter you called this hook with. It is included in the result so the
      * form manager can be passed on to field controls and they have access to the submitting state.
      */
     isSubmitting,
diff --git a/packages/simple-form/src/utils.ts b/packages/simple-form/src/utils.ts
index 197be70..45617c4 100644
--- a/packages/simple-form/src/utils.ts
+++ b/packages/simple-form/src/utils.ts
@@ -74,7 +74,7 @@ export const getFieldValues = <TFields>(formState: FormState<TFields>, fieldName
   return values;
 };
 
-export const getModifiedFieldValues = <T extends Record<string, unknown>>(initialFieldValues: T, fieldValues: T) => {
+export const getModifiedFieldValues = <TFields, T extends MakeNullable<TFields>>(initialFieldValues: T, fieldValues: T) => {
   const initialFieldValueEntries = new Map(Object.entries(initialFieldValues));
   const fieldValueEntries = Object.entries(fieldValues);
   return Object.fromEntries(
@@ -82,5 +82,5 @@ export const getModifiedFieldValues = <T extends Record<string, unknown>>(initia
       const initialValue = initialFieldValueEntries.get(key);
       return !isEqual(value, initialValue);
     })
-  );
+  ) as Partial<T>;
 };