diff --git a/src/filter.c b/src/filter.c
index edf1ed84b..b9782f043 100644
--- a/src/filter.c
+++ b/src/filter.c
@@ -268,7 +268,7 @@ int filter_tee_header (struct filter *chain)
 		fprintf (to_h, "#define %sIN_HEADER 1\n\n", ctrl.prefix);
 		fprintf (to_h,
 			 "m4_define( [[M4_YY_OUTFILE_NAME]],[[%s]])m4_dnl\n",
-			 headerfilename ? headerfilename : "<stdout>");
+			 env.headerfilename != NULL ? env.headerfilename : "<stdout>");
 
 	}
 
@@ -363,7 +363,7 @@ int filter_fix_linedirs (struct filter *chain)
 				env.outfilename != NULL ? env.outfilename : "<stdout>")
 					== 0
 			 || strcmp (fname,
-			 	headerfilename ? headerfilename : "<stdout>")
+			 	env.headerfilename != NULL ? env.headerfilename : "<stdout>")
 					== 0) {
 
 				char    *s1, *s2;
diff --git a/src/flexdef.h b/src/flexdef.h
index ea049c118..c39bacca0 100644
--- a/src/flexdef.h
+++ b/src/flexdef.h
@@ -384,7 +384,7 @@ struct ctrl_bundle_t {
        				// otherwise, use fread(). 
 	char *yyclass;		// yyFlexLexer subclass to use for YY_DECL 
 	bool yytext_is_array;	// if true (i.e., %array directive), then declare
-				//  yytext as a array instead of a character pointer.
+				// yytext as array instead of a character pointer.
 				// Nice and inefficient.
 };
 
@@ -396,6 +396,7 @@ struct env_bundle_t {
 	bool backing_up_report;	// (-b flag), generate "lex.backup" file 
 				// listing backing-up states
 	bool did_outfilename;	// whether outfilename was explicitly set
+	char *headerfilename;	// name of the .h file to generate
 	bool nowarn;		// (-w) do not generate warnings 
 	int performance_hint;	// if > 0 (i.e., -p flag), generate a report 
 				// relating to scanner performance; 
@@ -447,7 +448,6 @@ extern struct flex_backend_t *backend;
  * yyin - input file
  * infilename - name of input file
  * outfilename - name of output file
- * headerfilename - name of the .h file to generate
  * input_files - array holding names of input files
  * num_input_files - size of input_files array
  * program_name - name with which program was invoked
@@ -464,7 +464,7 @@ extern struct flex_backend_t *backend;
 
 extern int datapos, dataline, linenum;
 extern int skel_ind;
-extern char *infilename, *headerfilename;
+extern char *infilename;
 extern char *extra_type;
 extern char **input_files;
 extern int num_input_files;
diff --git a/src/main.c b/src/main.c
index 1750607bb..f6a4d2c46 100644
--- a/src/main.c
+++ b/src/main.c
@@ -56,7 +56,7 @@ int     skel_ind = 0;
 char   *action_array;
 int     action_size, defs1_offset, prolog_offset, action_offset,
 	action_index;
-char   *infilename = NULL, *headerfilename = NULL;
+char   *infilename = NULL;
 char   *extra_type = NULL;
 int     onestate[ONE_STACK_SIZE], onesym[ONE_STACK_SIZE];
 int     onenext[ONE_STACK_SIZE], onedef[ONE_STACK_SIZE], onesp;
@@ -324,7 +324,7 @@ void check_options (void)
 
 
 	/* Setup the filter chain. */
-	output_chain = filter_create_int(NULL, filter_tee_header, headerfilename);
+	output_chain = filter_create_int(NULL, filter_tee_header, env.headerfilename);
 	if ( !(m4 = getenv("M4"))) {
 		char *slash;
 		m4 = M4;
@@ -941,7 +941,7 @@ void flexinit (int argc, char **argv)
 			break;
 
 		    case OPT_HEADER_FILE:
-			headerfilename = arg;
+			env.headerfilename = arg;
 			break;
 
 		    case OPT_META_ECS:
@@ -1571,7 +1571,7 @@ void usage (void)
 
 	if (!env.did_outfilename) {
 		snprintf (outfile_path, sizeof(outfile_path), outfile_template,
-			 ctrl.prefix, ctrl.C_plus_plus ? "cc" : "c");
+			  ctrl.prefix, backend->suffix());
 		env.outfilename = outfile_path;
 	}
 
diff --git a/src/parse.y b/src/parse.y
index ae4b82fee..1a7e1bbef 100644
--- a/src/parse.y
+++ b/src/parse.y
@@ -205,7 +205,7 @@ option		:  TOK_OUTFILE '=' NAME
 		|  TOK_YYCLASS '=' NAME
 			{ ctrl.yyclass = xstrdup(nmstr); }
 		|  TOK_HEADER_FILE '=' NAME
-			{ headerfilename = xstrdup(nmstr); }
+			{ env.headerfilename = xstrdup(nmstr); }
 	    |  TOK_TABLES_FILE '=' NAME
             { tablesext = true; tablesfilename = xstrdup(nmstr); }
 		;