diff --git a/lib/lrama/command.rb b/lib/lrama/command.rb
index 213b7acb..eff31e46 100644
--- a/lib/lrama/command.rb
+++ b/lib/lrama/command.rb
@@ -8,7 +8,7 @@ def run(argv)
       warning = Lrama::Warning.new
       text = options.y.read
       options.y.close if options.y != STDIN
-      grammar = Lrama::NewParser.new(text).parse
+      grammar = Lrama::NewParser.new(text, options.header_file).parse
       states = Lrama::States.new(grammar, warning, trace_state: (options.trace_opts[:automaton] || options.trace_opts[:closure]))
       states.compute
       context = Lrama::Context.new(states)
diff --git a/lib/lrama/new_parser.rb b/lib/lrama/new_parser.rb
index a18e127a..2bfd6a66 100644
--- a/lib/lrama/new_parser.rb
+++ b/lib/lrama/new_parser.rb
@@ -10,8 +10,9 @@ class NewParser < Racc::Parser
 
 module_eval(<<'...end parser.y/module_eval...', 'parser.y', 121)
 
-def initialize(text)
+def initialize(text, header_file)
   @text = text
+  @header_path = header_file ? header_file.sub("./", "") : nil
   @lineno = []
   @column = []
 end
@@ -41,6 +42,14 @@ def build_token(type:, s_value:, line:, column:, alias_name: nil)
 
   token
 end
+
+def prologue(s_value)
+  if @header_path
+    "\n#include \"#{@header_path}\"\n" + s_value
+  else
+    s_value
+  end
+end
 ...end parser.y/module_eval...
 ##### State transition tables begin ###
 
@@ -474,7 +483,7 @@ def _reduce_5(val, _values, result)
 
 module_eval(<<'.,.,', 'parser.y', 7)
   def _reduce_6(val, _values, result)
-     @grammar.prologue = val[2]
+     @grammar.prologue = prologue(val[2])
     result
   end
 .,.,
diff --git a/parser.y b/parser.y
index 9f601011..a241f1c7 100644
--- a/parser.y
+++ b/parser.y
@@ -5,7 +5,7 @@ rule
   prologue_declarations: # empty
                        | prologue_declarations prologue_declaration
 
-  prologue_declaration: "%{" {@lexer.status = :c_declaration; @lexer.end_symbol = '%}'; @grammar.prologue_first_lineno = @lexer.line} C_DECLARATION {@lexer.status = :initial; @lexer.end_symbol = nil} "%}" { @grammar.prologue = val[2] }
+  prologue_declaration: "%{" {@lexer.status = :c_declaration; @lexer.end_symbol = '%}'; @grammar.prologue_first_lineno = @lexer.line} C_DECLARATION {@lexer.status = :initial; @lexer.end_symbol = nil} "%}" { @grammar.prologue = prologue(val[2]) }
                       | "%require" STRING
 
   bison_declarations: /* empty */ { result = "" }
@@ -119,8 +119,9 @@ end
 
 ---- inner
 
-def initialize(text)
+def initialize(text, header_file)
   @text = text
+  @header_path = header_file ? header_file.sub("./", "") : nil
   @lineno = []
   @column = []
 end
@@ -150,3 +151,11 @@ def build_token(type:, s_value:, line:, column:, alias_name: nil)
 
   token
 end
+
+def prologue(s_value)
+  if @header_path
+    "\n#include \"#{@header_path}\"\n" + s_value
+  else
+    s_value
+  end
+end