diff --git a/CHANGELOG.md b/CHANGELOG.md
index 66bfa5a..d941a26 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,7 @@
 ## HEAD (unreleased)
 
+- Fix bug where not all of a source is lexed which is used in heredoc detection/removal (https://github.com/zombocom/syntax_search/pull/23)
+
 ## 0.1.5
 
 - Strip out heredocs in documents first (https://github.com/zombocom/syntax_search/pull/19)
diff --git a/lib/syntax_search.rb b/lib/syntax_search.rb
index 2658f6e..c58a844 100644
--- a/lib/syntax_search.rb
+++ b/lib/syntax_search.rb
@@ -142,3 +142,4 @@ def self.invalid_type(source)
 require_relative "syntax_search/code_search"
 require_relative "syntax_search/who_dis_syntax_error"
 require_relative "syntax_search/heredoc_block_parse"
+require_relative "syntax_search/lex_all"
diff --git a/lib/syntax_search/heredoc_block_parse.rb b/lib/syntax_search/heredoc_block_parse.rb
index c521baf..9617530 100644
--- a/lib/syntax_search/heredoc_block_parse.rb
+++ b/lib/syntax_search/heredoc_block_parse.rb
@@ -7,19 +7,19 @@ class HeredocBlockParse
 
     def initialize(source:, code_lines: )
       @code_lines = code_lines
-      @lex = Ripper.lex(source)
+      @lex = LexAll.new(source: source)
     end
 
     def call
       blocks = []
       beginning = []
-      @lex.each do |(line, col), event, *_|
-        case event
+      @lex.each do |lex|
+        case lex.type
         when :on_heredoc_beg
-          beginning << line
+          beginning << lex.line
         when :on_heredoc_end
           start_index = beginning.pop - 1
-          end_index = line - 1
+          end_index = lex.line - 1
           blocks << CodeBlock.new(lines: code_lines[start_index..end_index])
         end
       end
diff --git a/lib/syntax_search/lex_all.rb b/lib/syntax_search/lex_all.rb
new file mode 100644
index 0000000..11a4305
--- /dev/null
+++ b/lib/syntax_search/lex_all.rb
@@ -0,0 +1,58 @@
+module SyntaxErrorSearch
+  # Ripper.lex is not guaranteed to lex the entire source document
+  #
+  # lex = LexAll.new(source: source)
+  # lex.each do |value|
+  #   puts value.line
+  # end
+  class LexAll
+    include Enumerable
+
+    def initialize(source: )
+      @lex = Ripper.lex(source)
+      lineno = @lex.last&.first&.first + 1
+      source_lines = source.lines
+      last_lineno = source_lines.count
+
+      until lineno >= last_lineno
+        lines = source_lines[lineno..-1]
+
+        @lex.concat(Ripper.lex(lines.join, '-', lineno + 1))
+        lineno = @lex.last&.first&.first + 1
+      end
+
+      @lex.map! {|(line, _), type, token| LexValue.new(line, _, type, token) }
+    end
+
+    def each
+      return @lex.each unless block_given?
+      @lex.each do |x|
+        yield x
+      end
+    end
+
+    def last
+      @lex.last
+    end
+
+    # Value object for accessing lex values
+    #
+    # This lex:
+    #
+    #   [1, 0], :on_ident, "describe", CMDARG
+    #
+    # Would translate into:
+    #
+    #  lex.line # => 1
+    #  lex.type # => :on_indent
+    #  lex.token # => "describe"
+    class LexValue
+      attr_reader :line, :type, :token
+      def initialize(line, _, type, token)
+        @line = line
+        @type = type
+        @token = token
+      end
+    end
+  end
+end
diff --git a/spec/unit/lex_all_spec.rb b/spec/unit/lex_all_spec.rb
new file mode 100644
index 0000000..10c69f2
--- /dev/null
+++ b/spec/unit/lex_all_spec.rb
@@ -0,0 +1,29 @@
+# frozen_string_literal: true
+
+require_relative "../spec_helper.rb"
+
+module SyntaxErrorSearch
+  RSpec.describe "EndBlockParse" do
+    it "finds blocks based on `end` keyword" do
+      source = <<~EOM
+        describe "cat" # 1
+          Cat.call do  # 2
+          end          # 3
+        end            # 4
+                       # 5
+        it "dog" do    # 6
+          Dog.call do  # 7
+          end          # 8
+        end            # 9
+      EOM
+
+      raw_lex = Ripper.lex(source)
+      expect(raw_lex.to_s).to_not include("dog")
+
+      lex = LexAll.new(source: source)
+      expect(lex.map(&:token).to_s).to include("dog")
+      expect(lex.first.line).to eq(1)
+      expect(lex.last.line).to eq(9)
+    end
+  end
+end