diff --git a/Demo/LCActionSheetDemo/ViewController.m b/Demo/LCActionSheetDemo/ViewController.m
index 2371d54..e992485 100644
--- a/Demo/LCActionSheetDemo/ViewController.m
+++ b/Demo/LCActionSheetDemo/ViewController.m
@@ -103,7 +103,7 @@ - (IBAction)showBlockActionSheet {
         NSMutableIndexSet *set = [[NSMutableIndexSet alloc] init];
         [set addIndex:1];
         [set addIndex:2];
-        [actionSheet appendButtonsWithTitles:@[@"Hello", @"World"] atIndexSet:set];
+        [actionSheet appendButtonsWithTitles:@[@"Hello", @"World"] atIndexes:set];
     });
 }
 
diff --git a/README.md b/README.md
index a35e95e..2ed3c32 100644
--- a/README.md
+++ b/README.md
@@ -141,7 +141,7 @@ In me the tiger sniffs the rose.
         NSMutableIndexSet *set = [[NSMutableIndexSet alloc] init];
         [set addIndex:1];
         [set addIndex:2];
-        [actionSheet appendButtonsWithTitles:@[@"Hello", @"World"] atIndexSet:set];
+        [actionSheet appendButtonsWithTitles:@[@"Hello", @"World"] atIndexes:set];
     });
     
     [actionSheet show];
@@ -288,7 +288,7 @@ In me the tiger sniffs the rose.
   - (void)appendButtonWithTitle:(nullable NSString *)title atIndex:(NSUInteger)index;
   
   // Append buttons at indexes with titles.
-  - (void)appendButtonsWithTitles:(NSArray<NSString *> *)titles atIndexSet:(NSIndexSet *)indexSet;
+  - (void)appendButtonsWithTitles:(NSArray<NSString *> *)titles atIndexex:(NSIndexSet *)indexes;
   
   @end
   ```
diff --git a/Sources/LCActionSheet.h b/Sources/LCActionSheet.h
index a66c92d..3f173c1 100644
--- a/Sources/LCActionSheet.h
+++ b/Sources/LCActionSheet.h
@@ -374,12 +374,12 @@ typedef void(^LCActionSheetDidDismissHandler)(LCActionSheet *actionSheet, NSUInt
 - (void)appendButtonWithTitle:(nullable NSString *)title atIndex:(NSUInteger)index;
 
 /**
- Append buttons at indexes with titles.
+ Append buttons at indexSet with titles.
 
  @param titles   titles
  @param indexSet indexSet
  */
-- (void)appendButtonsWithTitles:(NSArray<NSString *> *)titles atIndexSet:(NSIndexSet *)indexSet;
+- (void)appendButtonsWithTitles:(NSArray<NSString *> *)titles atIndexex:(NSIndexSet *)indexes;
 
 /**
  Show the instance of LCActionSheet.
diff --git a/Sources/LCActionSheet.m b/Sources/LCActionSheet.m
index 4506851..31ebcbc 100644
--- a/Sources/LCActionSheet.m
+++ b/Sources/LCActionSheet.m
@@ -389,16 +389,16 @@ - (void)appendButtonWithTitle:(NSString *)title atIndex:(NSUInteger)index {
     [self updateTableView];
 }
 
-- (void)appendButtonsWithTitles:(NSArray<NSString *> *)titles atIndexSet:(NSIndexSet *)indexSet {
+- (void)appendButtonsWithTitles:(NSArray<NSString *> *)titles atIndexes:(NSIndexSet *)indexes {
 #ifdef DEBUG
-    NSAssert(titles.count == indexSet.count, @"Count of titles differs from count of indexs");
+    NSAssert(titles.count == indexes.count, @"Count of titles differs from count of indexs");
 #endif
     
     NSMutableIndexSet *indexSetM = [[NSMutableIndexSet alloc] init];
-    [indexSet enumerateIndexesUsingBlock:^(NSUInteger idx, BOOL * _Nonnull stop) {
+    [indexes enumerateIndexesUsingBlock:^(NSUInteger idx, BOOL * _Nonnull stop) {
 #ifdef DEBUG
         NSAssert(idx != 0, @"Index 0 is cancel button");
-        NSAssert(idx <= self.otherButtonTitles.count + indexSet.count, @"Index crossed");
+        NSAssert(idx <= self.otherButtonTitles.count + indexes.count, @"Index crossed");
 #endif
         
         [indexSetM addIndex:idx - 1];