diff --git a/assets/parser.h.erb b/assets/parser.h.erb
index 7796e4c..a9927b6 100644
--- a/assets/parser.h.erb
+++ b/assets/parser.h.erb
@@ -4,8 +4,7 @@
  * This file is generated by Propane.
  */
 
-#ifndef PROPANE_PARSER_H
-#define PROPANE_PARSER_H
+#pragma once
 
 #include <stdint.h>
 #include <stddef.h>
@@ -121,5 +120,3 @@ size_t <%= @grammar.prefix %>parse(<%= @grammar.prefix %>context_t * context);
 <%= start_rule_type[1] %> <%= @grammar.prefix %>result(<%= @grammar.prefix %>context_t * context);
 
 <%= @grammar.prefix %>position_t <%= @grammar.prefix %>position(<%= @grammar.prefix %>context_t * context);
-
-#endif
diff --git a/spec/test_multiple_parsers.c b/spec/test_multiple_parsers.c
new file mode 100644
index 0000000..cad14a7
--- /dev/null
+++ b/spec/test_multiple_parsers.c
@@ -0,0 +1,19 @@
+#include "testparsermyp1.h"
+#include "testparsermyp2.h"
+#include <assert.h>
+#include <string.h>
+
+int main()
+{
+    char const * input1 = "a\n1";
+    myp1_context_t context1;
+    myp1_context_init(&context1, (uint8_t const *)input1, strlen(input1));
+    assert(myp1_parse(&context1) == MYP1_SUCCESS);
+
+    char const * input2 = "bcb";
+    myp2_context_t context2;
+    myp2_context_init(&context2, (uint8_t const *)input2, strlen(input2));
+    assert(myp2_parse(&context2) == MYP2_SUCCESS);
+
+    return 0;
+}