diff --git a/lib/puppet/pops/parser/heredoc_support.rb b/lib/puppet/pops/parser/heredoc_support.rb
index d0bd1073edd..53bd2b0bc68 100644
--- a/lib/puppet/pops/parser/heredoc_support.rb
+++ b/lib/puppet/pops/parser/heredoc_support.rb
@@ -98,8 +98,7 @@ def heredoc
 
         # Use a new lexer instance configured with a sub-locator to enable correct positioning
         sublexer = self.class.new()
-        locator = Locator::SubLocator.sub_locator(str,
-          locator.file, heredoc_line, heredoc_offset, leading.length())
+        locator = Locator::SubLocator.new(locator, heredoc_line, heredoc_offset, leading.length())
 
         # Emit a token that provides the grammar with location information about the lines on which the heredoc
         # content is based.
diff --git a/lib/puppet/pops/parser/lexer2.rb b/lib/puppet/pops/parser/lexer2.rb
index d095f69a956..c31bfd6aef8 100644
--- a/lib/puppet/pops/parser/lexer2.rb
+++ b/lib/puppet/pops/parser/lexer2.rb
@@ -189,7 +189,7 @@ def initialize()
       ',' => lambda {  emit(TOKEN_COMMA, @scanner.pos) },
       '[' => lambda do
         before = @scanner.pos
-        if (before == 0 || @scanner.string[locator.char_offset(before)-1,1] =~ /[[:blank:]\r\n]+/)
+        if (before == 0 || locator.string[locator.char_offset(before)-1,1] =~ /[[:blank:]\r\n]+/)
           emit(TOKEN_LISTSTART, before)
         else
           emit(TOKEN_LBRACK, before)
diff --git a/spec/unit/pops/parser/parse_heredoc_spec.rb b/spec/unit/pops/parser/parse_heredoc_spec.rb
index 5a7b60aa50d..3b7006517f4 100644
--- a/spec/unit/pops/parser/parse_heredoc_spec.rb
+++ b/spec/unit/pops/parser/parse_heredoc_spec.rb
@@ -140,6 +140,22 @@
     ].join("\n"))
   end
 
+  it "parses interpolated [] expression by looking at the correct preceding char for space" do
+    # NOTE: Important not to use the left margin feature here
+    src = <<-CODE
+$xxxxxxx = @("END")
+${facts['os']['family']}
+XXXXXXX XXX
+END
+CODE
+    expect(dump(parse(src))).to eq([
+      "(= $xxxxxxx (@()",
+      "  (sublocated (cat (str (slice (slice $facts 'os') 'family')) '",
+      "XXXXXXX XXX",
+      "'))",
+      "))"].join("\n"))
+  end
+
   it 'parses multiple heredocs on the same line' do
     src = <<-CODE
     notice({ @(foo) => @(bar) })