diff --git a/mrbgems/mruby-array-ext/mrblib/array.rb b/mrbgems/mruby-array-ext/mrblib/array.rb
index cdc2e0226..f1f5840e2 100644
--- a/mrbgems/mruby-array-ext/mrblib/array.rb
+++ b/mrbgems/mruby-array-ext/mrblib/array.rb
@@ -62,7 +62,7 @@ class Array
 
   # for efficiency
   def reverse_each(&block)
-    return to_enum :reverse_each unless block
+    return to_enum(:reverse_each) unless block
 
     i = self.size - 1
     while i>=0
@@ -187,7 +187,7 @@ class Array
   #     scores.delete_if {|score| score < 80 }   #=> [97]
 
   def delete_if(&block)
-    return to_enum :delete_if unless block
+    return to_enum(:delete_if) unless block
 
     result = []
     idx = 0
@@ -217,7 +217,7 @@ class Array
   #  If no block is given, an Enumerator is returned instead.
 
   def reject!(&block)
-    return to_enum :reject! unless block
+    return to_enum(:reject!) unless block
 
     result = []
     idx = 0
@@ -288,7 +288,7 @@ class Array
   #  undefined which value is actually picked up at each iteration.
 
   def bsearch(&block)
-    return to_enum :bsearch unless block
+    return to_enum(:bsearch) unless block
 
     if idx = bsearch_index(&block)
       self[idx]
@@ -310,7 +310,7 @@ class Array
   #  element itself. For more details consult the documentation for #bsearch.
 
   def bsearch_index(&block)
-    return to_enum :bsearch_index unless block
+    return to_enum(:bsearch_index) unless block
 
     low = 0
     high = size
@@ -360,7 +360,7 @@ class Array
   #     a.keep_if { |val| val > 3 } #=> [4, 5]
 
   def keep_if(&block)
-    return to_enum :keep_if unless block
+    return to_enum(:keep_if) unless block
 
     result = []
     idx = 0
@@ -389,7 +389,7 @@ class Array
   #  If no block is given, an Enumerator is returned instead.
 
   def select!(&block)
-    return to_enum :select! unless block
+    return to_enum(:select!) unless block
 
     result = []
     idx = 0