diff --git a/lib/fluent/plugin_helper/record_accessor.rb b/lib/fluent/plugin_helper/record_accessor.rb
index 9a37a60ff4..3db05965db 100644
--- a/lib/fluent/plugin_helper/record_accessor.rb
+++ b/lib/fluent/plugin_helper/record_accessor.rb
@@ -140,7 +140,7 @@ def self.parse_dot_array_op(key, param)
               if i = key.index(']')
                 index_value = key[0..i - 1]
                 raise Fluent::ConfigError, "missing array index in '[]'. Invalid syntax: #{param}" if index_value == ']'
-                result << Integer(index_value)
+                result << parse_array_index(index_value, param)
                 key = key[i + 1..-1]
                 in_bracket = false
               else
@@ -159,6 +159,12 @@ def self.parse_dot_array_op(key, param)
           result
         end
 
+        def self.parse_array_index(index_value, param)
+          Integer(index_value)
+        rescue ArgumentError
+          raise Fluent::ConfigError, "array index must be an integer: '#{index_value}'. Invalid syntax: #{param}"
+        end
+
         def self.parse_bracket_notation(param)
           orig_param = param
           result = []
@@ -180,7 +186,7 @@ def self.parse_bracket_notation(param)
                 if i = param.index(']')
                   index_value = param[0..i - 1]
                   raise Fluent::ConfigError, "missing array index in '[]'. Invalid syntax: #{param}" if index_value == ']'
-                  result << Integer(index_value)
+                  result << parse_array_index(index_value, orig_param)
                   param = param[i + 1..-1]
                   in_bracket = false
                 else
diff --git a/test/plugin_helper/test_record_accessor.rb b/test/plugin_helper/test_record_accessor.rb
index 4d2b9a4198..5a89d75e17 100644
--- a/test/plugin_helper/test_record_accessor.rb
+++ b/test/plugin_helper/test_record_accessor.rb
@@ -49,6 +49,8 @@ class Dummy < Fluent::Plugin::TestBase
     data("missing ']'" => "$['key1'",
          "missing array index with dot" => "$.hello[]",
          "missing array index with bracket" => "$[]",
+         "non-integer array index with dot" => "$.key1[x]",
+         "non-integer array index with bracket" => "$['key1'][x]",
          "more chars" => "$.key1[0]foo",
          "whitespace char included key in dot notation" => "$.key[0].ke y",
          "empty keys with dot" => "$.",
@@ -142,6 +144,8 @@ class Dummy < Fluent::Plugin::TestBase
     data("missing ']'" => "$['key1'",
          "missing array index with dot" => "$.hello[]",
          "missing array index with bracket" => "$['hello'][]",
+         "non-integer array index with dot" => "$.key1[x]",
+         "non-integer array index with bracket" => "$['key1'][x]",
          "whitespace char included key in dot notation" => "$.key[0].ke y",
          "more chars" => "$.key1[0]foo",
          "empty keys with dot" => "$.",