diff --git a/lib/puppet/parser/functions/hiera.rb b/lib/puppet/parser/functions/hiera.rb
deleted file mode 100644
index 82946769e3..0000000000
--- a/lib/puppet/parser/functions/hiera.rb
+++ /dev/null
@@ -1,105 +0,0 @@
-# frozen_string_literal: true
-
-require 'hiera_puppet'
-
-module Puppet::Parser::Functions
-  newfunction(
-    :hiera,
-    :type => :rvalue,
-    :arity => -2,
-    :doc => <<~DOC
-      Performs a standard priority lookup of the hierarchy and returns the most specific value
-      for a given key. The returned value can be any type of data.
-
-      The function takes up to three arguments, in this order:
-
-      1. A string key that Hiera searches for in the hierarchy. **Required**.
-      2. An optional default value to return if Hiera doesn't find anything matching the key.
-          * If this argument isn't provided and this function results in a lookup failure, Puppet
-          fails with a compilation error.
-      3. The optional name of an arbitrary
-      [hierarchy level](https://puppet.com/docs/hiera/latest/hierarchy.html) to insert at the
-      top of the hierarchy. This lets you temporarily modify the hierarchy for a single lookup.
-          * If Hiera doesn't find a matching key in the overriding hierarchy level, it continues
-          searching the rest of the hierarchy.
-
-      The `hiera` function does **not** find all matches throughout a hierarchy, instead
-      returining the first specific value starting at the top of the hierarchy. To search
-      throughout a hierarchy, use the `hiera_array` or `hiera_hash` functions.
-
-      **Example**: Using `hiera`
-
-      ~~~ yaml
-      # Assuming hiera.yaml
-      # :hierarchy:
-      #   - web01.example.com
-      #   - common
-
-      # Assuming web01.example.com.yaml:
-      # users:
-      #   - "Amy Barry"
-      #   - "Carrie Douglas"
-
-      # Assuming common.yaml:
-      users:
-        admins:
-          - "Edith Franklin"
-          - "Ginny Hamilton"
-        regular:
-          - "Iris Jackson"
-          - "Kelly Lambert"
-      ~~~
-
-      ~~~ puppet
-      # Assuming we are not web01.example.com:
-
-      $users = hiera('users', undef)
-
-      # $users contains {admins  => ["Edith Franklin", "Ginny Hamilton"],
-      #                  regular => ["Iris Jackson", "Kelly Lambert"]}
-      ~~~
-
-      You can optionally generate the default value with a
-      [lambda](https://puppet.com/docs/puppet/latest/lang_lambdas.html) that
-      takes one parameter.
-
-      **Example**: Using `hiera` with a lambda
-
-      ~~~ puppet
-      # Assuming the same Hiera data as the previous example:
-
-      $users = hiera('users') | $key | { "Key \'${key}\' not found" }
-
-      # $users contains {admins  => ["Edith Franklin", "Ginny Hamilton"],
-      #                  regular => ["Iris Jackson", "Kelly Lambert"]}
-      # If hiera couldn't match its key, it would return the lambda result,
-      # "Key 'users' not found".
-      ~~~
-
-      The returned value's data type depends on the types of the results. In the example
-      above, Hiera matches the 'users' key and returns it as a hash.
-
-      The `hiera` function is deprecated in favor of using `lookup` and will be removed in 6.0.0.
-      See https://puppet.com/docs/puppet/#{Puppet.minor_version}/deprecated_language.html.
-      Replace the calls as follows:
-
-      | from  | to |
-      | ----  | ---|
-      | hiera($key) | lookup($key) |
-      | hiera($key, $default) | lookup($key, { 'default_value' => $default }) |
-      | hiera($key, $default, $level) | override level not supported |
-
-      Note that calls using the 'override level' option are not directly supported by 'lookup' and the produced
-      result must be post processed to get exactly the same result, for example using simple hash/array `+` or
-      with calls to stdlib's `deep_merge` function depending on kind of hiera call and setting of merge in hiera.yaml.
-
-      See
-      [the documentation](https://puppet.com/docs/hiera/latest/puppet.html#hiera-lookup-functions)
-      for more information about Hiera lookup functions.
-
-      - Since 4.0.0
-    DOC
-  ) do |*_args|
-    Error.is4x('hiera')
-  end
-end
diff --git a/lib/puppet/parser/functions/hiera_array.rb b/lib/puppet/parser/functions/hiera_array.rb
deleted file mode 100644
index 25bc729f11..0000000000
--- a/lib/puppet/parser/functions/hiera_array.rb
+++ /dev/null
@@ -1,93 +0,0 @@
-# frozen_string_literal: true
-
-require 'hiera_puppet'
-
-module Puppet::Parser::Functions
-  newfunction(
-    :hiera_array,
-    :type => :rvalue,
-    :arity => -2,
-    :doc => <<~DOC
-      Finds all matches of a key throughout the hierarchy and returns them as a single flattened
-      array of unique values. If any of the matched values are arrays, they're flattened and
-      included in the results. This is called an
-      [array merge lookup](https://puppet.com/docs/hiera/latest/lookup_types.html#array-merge).
-
-      The `hiera_array` function takes up to three arguments, in this order:
-
-      1. A string key that Hiera searches for in the hierarchy. **Required**.
-      2. An optional default value to return if Hiera doesn't find anything matching the key.
-          * If this argument isn't provided and this function results in a lookup failure, Puppet
-          fails with a compilation error.
-      3. The optional name of an arbitrary
-      [hierarchy level](https://puppet.com/docs/hiera/latest/hierarchy.html) to insert at the
-      top of the hierarchy. This lets you temporarily modify the hierarchy for a single lookup.
-          * If Hiera doesn't find a matching key in the overriding hierarchy level, it continues
-          searching the rest of the hierarchy.
-
-      **Example**: Using `hiera_array`
-
-      ~~~ yaml
-      # Assuming hiera.yaml
-      # :hierarchy:
-      #   - web01.example.com
-      #   - common
-
-      # Assuming common.yaml:
-      # users:
-      #   - 'cdouglas = regular'
-      #   - 'efranklin = regular'
-
-      # Assuming web01.example.com.yaml:
-      # users: 'abarry = admin'
-      ~~~
-
-      ~~~ puppet
-      $allusers = hiera_array('users', undef)
-
-      # $allusers contains ["cdouglas = regular", "efranklin = regular", "abarry = admin"].
-      ~~~
-
-      You can optionally generate the default value with a
-      [lambda](https://puppet.com/docs/puppet/latest/lang_lambdas.html) that
-      takes one parameter.
-
-      **Example**: Using `hiera_array` with a lambda
-
-      ~~~ puppet
-      # Assuming the same Hiera data as the previous example:
-
-      $allusers = hiera_array('users') | $key | { "Key \'${key}\' not found" }
-
-      # $allusers contains ["cdouglas = regular", "efranklin = regular", "abarry = admin"].
-      # If hiera_array couldn't match its key, it would return the lambda result,
-      # "Key 'users' not found".
-      ~~~
-
-      `hiera_array` expects that all values returned will be strings or arrays. If any matched
-      value is a hash, Puppet raises a type mismatch error.
-
-      `hiera_array` is deprecated in favor of using `lookup` and will be removed in 6.0.0.
-      See https://puppet.com/docs/puppet/#{Puppet.minor_version}/deprecated_language.html.
-      Replace the calls as follows:
-
-      | from  | to |
-      | ----  | ---|
-      | hiera_array($key) | lookup($key, { 'merge' => 'unique' }) |
-      | hiera_array($key, $default) | lookup($key, { 'default_value' => $default, 'merge' => 'unique' }) |
-      | hiera_array($key, $default, $level) | override level not supported |
-
-      Note that calls using the 'override level' option are not directly supported by 'lookup' and the produced
-      result must be post processed to get exactly the same result, for example using simple hash/array `+` or
-      with calls to stdlib's `deep_merge` function depending on kind of hiera call and setting of merge in hiera.yaml.
-
-      See
-      [the documentation](https://puppet.com/docs/hiera/latest/puppet.html#hiera-lookup-functions)
-      for more information about Hiera lookup functions.
-
-      - Since 4.0.0
-    DOC
-  ) do |*_args|
-    Error.is4x('hiera_array')
-  end
-end
diff --git a/lib/puppet/parser/functions/hiera_hash.rb b/lib/puppet/parser/functions/hiera_hash.rb
deleted file mode 100644
index 4cf4681768..0000000000
--- a/lib/puppet/parser/functions/hiera_hash.rb
+++ /dev/null
@@ -1,103 +0,0 @@
-# frozen_string_literal: true
-
-require 'hiera_puppet'
-
-module Puppet::Parser::Functions
-  newfunction(
-    :hiera_hash,
-    :type => :rvalue,
-    :arity => -2,
-    :doc => <<~DOC
-      Finds all matches of a key throughout the hierarchy and returns them in a merged hash.
-      If any of the matched hashes share keys, the final hash uses the value from the
-      highest priority match. This is called a
-      [hash merge lookup](https://puppet.com/docs/hiera/latest/lookup_types.html#hash-merge).
-
-      The merge strategy is determined by Hiera's
-      [`:merge_behavior`](https://puppet.com/docs/hiera/latest/configuring.html#mergebehavior)
-      setting.
-
-      The `hiera_hash` function takes up to three arguments, in this order:
-
-      1. A string key that Hiera searches for in the hierarchy. **Required**.
-      2. An optional default value to return if Hiera doesn't find anything matching the key.
-          * If this argument isn't provided and this function results in a lookup failure, Puppet
-          fails with a compilation error.
-      3. The optional name of an arbitrary
-      [hierarchy level](https://puppet.com/docs/hiera/latest/hierarchy.html) to insert at the
-      top of the hierarchy. This lets you temporarily modify the hierarchy for a single lookup.
-          * If Hiera doesn't find a matching key in the overriding hierarchy level, it continues
-          searching the rest of the hierarchy.
-
-      **Example**: Using `hiera_hash`
-
-      ~~~ yaml
-      # Assuming hiera.yaml
-      # :hierarchy:
-      #   - web01.example.com
-      #   - common
-
-      # Assuming common.yaml:
-      # users:
-      #   regular:
-      #     'cdouglas': 'Carrie Douglas'
-
-      # Assuming web01.example.com.yaml:
-      # users:
-      #   administrators:
-      #     'aberry': 'Amy Berry'
-      ~~~
-
-      ~~~ puppet
-      # Assuming we are not web01.example.com:
-
-      $allusers = hiera_hash('users', undef)
-
-      # $allusers contains {regular => {"cdouglas" => "Carrie Douglas"},
-      #                     administrators => {"aberry" => "Amy Berry"}}
-      ~~~
-
-      You can optionally generate the default value with a
-      [lambda](https://puppet.com/docs/puppet/latest/lang_lambdas.html) that
-      takes one parameter.
-
-      **Example**: Using `hiera_hash` with a lambda
-
-      ~~~ puppet
-      # Assuming the same Hiera data as the previous example:
-
-      $allusers = hiera_hash('users') | $key | { "Key \'${key}\' not found" }
-
-      # $allusers contains {regular => {"cdouglas" => "Carrie Douglas"},
-      #                     administrators => {"aberry" => "Amy Berry"}}
-      # If hiera_hash couldn't match its key, it would return the lambda result,
-      # "Key 'users' not found".
-      ~~~
-
-      `hiera_hash` expects that all values returned will be hashes. If any of the values
-      found in the data sources are strings or arrays, Puppet raises a type mismatch error.
-
-      `hiera_hash` is deprecated in favor of using `lookup` and will be removed in 6.0.0.
-      See  https://puppet.com/docs/puppet/#{Puppet.minor_version}/deprecated_language.html.
-      Replace the calls as follows:
-
-      | from  | to |
-      | ----  | ---|
-      | hiera_hash($key) | lookup($key, { 'merge' => 'hash' }) |
-      | hiera_hash($key, $default) | lookup($key, { 'default_value' => $default, 'merge' => 'hash' }) |
-      | hiera_hash($key, $default, $level) | override level not supported |
-
-      Note that calls using the 'override level' option are not directly supported by 'lookup' and the produced
-      result must be post processed to get exactly the same result, for example using simple hash/array `+` or
-      with calls to stdlib's `deep_merge` function depending on kind of hiera call and setting of merge in hiera.yaml.
-
-      See
-      [the documentation](https://puppet.com/docs/hiera/latest/puppet.html#hiera-lookup-functions)
-      for more information about Hiera lookup functions.
-
-      - Since 4.0.0
-    DOC
-  ) do |*_args|
-    Error.is4x('hiera_hash')
-  end
-end
diff --git a/lib/puppet/parser/functions/hiera_include.rb b/lib/puppet/parser/functions/hiera_include.rb
deleted file mode 100644
index b925fb4e1c..0000000000
--- a/lib/puppet/parser/functions/hiera_include.rb
+++ /dev/null
@@ -1,102 +0,0 @@
-# frozen_string_literal: true
-
-require 'hiera_puppet'
-
-module Puppet::Parser::Functions
-  newfunction(
-    :hiera_include,
-    :arity => -2,
-    :doc => <<~DOC
-      Assigns classes to a node using an
-      [array merge lookup](https://puppet.com/docs/hiera/latest/lookup_types.html#array-merge)
-      that retrieves the value for a user-specified key from Hiera's data.
-
-      The `hiera_include` function requires:
-
-      - A string key name to use for classes.
-      - A call to this function (i.e. `hiera_include('classes')`) in your environment's
-      `sites.pp` manifest, outside of any node definitions and below any top-scope variables
-      that Hiera uses in lookups.
-      - `classes` keys in the appropriate Hiera data sources, with an array for each
-      `classes` key and each value of the array containing the name of a class.
-
-      The function takes up to three arguments, in this order:
-
-      1. A string key that Hiera searches for in the hierarchy. **Required**.
-      2. An optional default value to return if Hiera doesn't find anything matching the key.
-          * If this argument isn't provided and this function results in a lookup failure, Puppet
-          fails with a compilation error.
-      3. The optional name of an arbitrary
-      [hierarchy level](https://puppet.com/docs/hiera/latest/hierarchy.html) to insert at the
-      top of the hierarchy. This lets you temporarily modify the hierarchy for a single lookup.
-          * If Hiera doesn't find a matching key in the overriding hierarchy level, it continues
-          searching the rest of the hierarchy.
-
-      The function uses an
-      [array merge lookup](https://puppet.com/docs/hiera/latest/lookup_types.html#array-merge)
-      to retrieve the `classes` array, so every node gets every class from the hierarchy.
-
-      **Example**: Using `hiera_include`
-
-      ~~~ yaml
-      # Assuming hiera.yaml
-      # :hierarchy:
-      #   - web01.example.com
-      #   - common
-
-      # Assuming web01.example.com.yaml:
-      # classes:
-      #   - apache::mod::php
-
-      # Assuming common.yaml:
-      # classes:
-      #   - apache
-      ~~~
-
-      ~~~ puppet
-      # In site.pp, outside of any node definitions and below any top-scope variables:
-      hiera_include('classes', undef)
-
-      # Puppet assigns the apache and apache::mod::php classes to the web01.example.com node.
-      ~~~
-
-      You can optionally generate the default value with a
-      [lambda](https://puppet.com/docs/puppet/latest/lang_lambdas.html) that
-      takes one parameter.
-
-      **Example**: Using `hiera_include` with a lambda
-
-      ~~~ puppet
-      # Assuming the same Hiera data as the previous example:
-
-      # In site.pp, outside of any node definitions and below any top-scope variables:
-      hiera_include('classes') | $key | {"Key \'${key}\' not found" }
-
-      # Puppet assigns the apache and apache::mod::php classes to the web01.example.com node.
-      # If hiera_include couldn't match its key, it would return the lambda result,
-      # "Key 'classes' not found".
-      ~~~
-
-      `hiera_include` is deprecated in favor of using a combination of `include` and `lookup` and will be
-      removed in Puppet 6.0.0. Replace the calls as follows:
-
-      | from  | to |
-      | ----  | ---|
-      | hiera_include($key) | include(lookup($key, { 'merge' => 'unique' })) |
-      | hiera_include($key, $default) | include(lookup($key, { 'default_value' => $default, 'merge' => 'unique' })) |
-      | hiera_include($key, $default, $level) | override level not supported |
-
-      See
-      [the Upgrading to Hiera 5 migration guide](https://puppet.com/docs/puppet/5.5/hiera_migrate.html)
-      for more information.
-
-      Note that calls using the 'override level' option are not directly supported by 'lookup' and the produced
-      result must be post processed to get exactly the same result, for example using simple hash/array `+` or
-      with calls to stdlib's `deep_merge` function depending on kind of hiera call and setting of merge in hiera.yaml.
-
-      - Since 4.0.0
-    DOC
-  ) do |*_args|
-    Error.is4x('hiera_include')
-  end
-end
diff --git a/spec/unit/parser/functions/hiera_array_spec.rb b/spec/unit/parser/functions/hiera_array_spec.rb
deleted file mode 100644
index fa41767a07..0000000000
--- a/spec/unit/parser/functions/hiera_array_spec.rb
+++ /dev/null
@@ -1,12 +0,0 @@
-require 'spec_helper'
-require 'puppet_spec/scope'
-
-describe 'Puppet::Parser::Functions#hiera_array' do
-  include PuppetSpec::Scope
-
-  let :scope do create_test_scope_for_node('foo') end
-
-  it 'should raise an error since this function is converted to 4x API)' do
-    expect { scope.function_hiera_array(['key']) }.to raise_error(Puppet::ParseError, /can only be called using the 4.x function API/)
-  end
-end
diff --git a/spec/unit/parser/functions/hiera_hash_spec.rb b/spec/unit/parser/functions/hiera_hash_spec.rb
deleted file mode 100644
index 935c499252..0000000000
--- a/spec/unit/parser/functions/hiera_hash_spec.rb
+++ /dev/null
@@ -1,12 +0,0 @@
-require 'spec_helper'
-require 'puppet_spec/scope'
-
-describe 'Puppet::Parser::Functions#hiera_hash' do
-  include PuppetSpec::Scope
-
-  let :scope do create_test_scope_for_node('foo') end
-
-  it 'should raise an error since this function is converted to 4x API)' do
-    expect { scope.function_hiera_hash(['key']) }.to raise_error(Puppet::ParseError, /can only be called using the 4.x function API/)
-  end
-end
diff --git a/spec/unit/parser/functions/hiera_include_spec.rb b/spec/unit/parser/functions/hiera_include_spec.rb
deleted file mode 100644
index 6a62ec8813..0000000000
--- a/spec/unit/parser/functions/hiera_include_spec.rb
+++ /dev/null
@@ -1,12 +0,0 @@
-require 'spec_helper'
-require 'puppet_spec/scope'
-
-describe 'Puppet::Parser::Functions#hiera_include' do
-  include PuppetSpec::Scope
-
-  let :scope do create_test_scope_for_node('foo') end
-
-  it 'should raise an error since this function is converted to 4x API)' do
-    expect { scope.function_hiera_include(['key']) }.to raise_error(Puppet::ParseError, /can only be called using the 4.x function API/)
-  end
-end
diff --git a/spec/unit/parser/functions/hiera_spec.rb b/spec/unit/parser/functions/hiera_spec.rb
deleted file mode 100644
index 42c33ad378..0000000000
--- a/spec/unit/parser/functions/hiera_spec.rb
+++ /dev/null
@@ -1,12 +0,0 @@
-require 'spec_helper'
-require 'puppet_spec/scope'
-
-describe 'Puppet::Parser::Functions#hiera' do
-  include PuppetSpec::Scope
-
-  let :scope do create_test_scope_for_node('foo') end
-
-  it 'should raise an error since this function is converted to 4x API)' do
-    expect { scope.function_hiera(['key']) }.to raise_error(Puppet::ParseError, /can only be called using the 4.x function API/)
-  end
-end