diff --git a/lib/core_ext/secure_random.rb b/lib/core_ext/secure_random.rb
deleted file mode 100644
index 5cc3c363..00000000
--- a/lib/core_ext/secure_random.rb
+++ /dev/null
@@ -1,23 +0,0 @@
-# From Rails 6
-# Remove once upgraded
-module SecureRandom
-  BASE36_ALPHABET = ("0".."9").to_a + ("a".."z").to_a
-  # SecureRandom.base36 generates a random base36 string in lowercase.
-  #
-  # The argument _n_ specifies the length of the random string to be generated.
-  #
-  # If _n_ is not specified or is +nil+, 16 is assumed. It may be larger in the future.
-  # This method can be used over +base58+ if a deterministic case key is necessary.
-  #
-  # The result will contain alphanumeric characters in lowercase.
-  #
-  #   p SecureRandom.base36 # => "4kugl2pdqmscqtje"
-  #   p SecureRandom.base36(24) # => "77tmhrhjfvfdwodq8w7ev2m7"
-  def self.base36(n = 16)
-    SecureRandom.random_bytes(n).unpack("C*").map do |byte|
-      idx = byte % 64
-      idx = SecureRandom.random_number(36) if idx >= 36
-      BASE36_ALPHABET[idx]
-    end.join
-  end
-end
\ No newline at end of file