diff --git a/lib/puppet/parser/functions/scanf.rb b/lib/puppet/parser/functions/scanf.rb
index c9677c86b..8872ae2a0 100644
--- a/lib/puppet/parser/functions/scanf.rb
+++ b/lib/puppet/parser/functions/scanf.rb
@@ -1,35 +1,44 @@
+require 'scanf'
+
 Puppet::Parser::Functions::newfunction(
   :scanf,
   :type => :rvalue,
   :arity => 2,
   :doc => <<-DOC
 Scans a string and returns an array of one or more converted values as directed by a given format string.args
 See the documenation of Ruby's String::scanf method for details about the supported formats (which
 are similar but not identical to the formats used in Puppet's `sprintf` function.
 
-This function takes two mandatory arguments: the first is the String to convert, and the second
-the format String. A parameterized block may optionally be given, which is called with the result
-that is produced by scanf if no block is present, the result of the block is then returned by
-the function.
+This function takes two mandatory arguments: the first is the String to
+convert, and the second the format String. The result of the scan is an Array,
+with each sucessfully scanned and transformed value.args The scanning stops if
+a scan is unsuccesful and the scanned result up to that point is returned. If
+there was no succesful scan at all, the result is an empty Array.
+
+      scanf("42", "%i")[0] == 42
+
 
-The result of the scan is an Array, with each sucessfully scanned and transformed value.args The scanning
-stops if a scan is unsuccesful and the scanned result up to that point is returned. If there was no
-succesful scan at all, the result is an empty Array. The optional code block is typically used to
-assert that the scan was succesful, and either produce the same input, or perform unwrapping of
-the result
+When used with the future parser, an optional parameterized block may be given.  
+The block is called with the result that is produced by scanf if no block is
+present, the result of the block is then returned by the function.
 
+The optional code block is typically used to assert that the scan was
+succesful, and either produce the same input, or perform unwrapping of
+the result:
 
       "42".scanf("%i")
       "42".scanf("%i") |$x| {
         unless $x[0] =~ Integer {
           fail "Expected a well formed integer value, got '$x[0]'"
         }
         $x[0]
       }
 
-- since 3.7.4
-- note requires `parser = future`
+- since 3.7.4 with `parser = future`
+- since 3.7.5 with classic parser
 DOC
 ) do |args|
-  function_fail(["scanf() is only available when parser/evaluator future is in effect"])
+  data = args[0]
+  format = args[1]
+  result = data.scanf(format)
 end
diff --git a/spec/unit/parser/functions/scanf_spec.rb b/spec/unit/parser/functions/scanf_spec.rb
new file mode 100755
index 000000000..45bb4a990
--- /dev/null
+++ b/spec/unit/parser/functions/scanf_spec.rb
@@ -0,0 +1,30 @@
+#! /usr/bin/env ruby
+require 'spec_helper'
+
+describe "the scanf function" do
+  before :all do
+    Puppet::Parser::Functions.autoloader.loadall
+  end
+
+  let(:node) { Puppet::Node.new('localhost') }
+  let(:compiler) { Puppet::Parser::Compiler.new(node) }
+  let(:scope) { Puppet::Parser::Scope.new(compiler) }
+
+  it 'scans a value and returns an array' do
+    expect(scope.function_scanf(['42', '%i'])[0] == 42)
+  end
+
+  it 'returns empty array if nothing was scanned' do
+    expect(scope.function_scanf(['no', '%i']) == [])
+  end
+
+  it 'produces result up to first unsuccessful scan' do
+    expect(scope.function_scanf(['42 no', '%i'])[0] == 42)
+  end
+
+  it 'errors when not given enough arguments' do
+    expect do
+      scope.function_scanf(['42'])
+    end.to raise_error(/.*scanf\(\): Wrong number of arguments given/m)
+  end
+end