diff --git a/lib/conf-parse.y b/lib/conf-parse.y
index a4504a37..cad8dd6b 100644
--- a/lib/conf-parse.y
+++ b/lib/conf-parse.y
@@ -29,6 +29,7 @@
 #include "error.h"
 #include "conf.h"
 #include "access.h"
+#include "init.h"
 
 /* These two functions are defined in conf-lex.l */
 extern int sensors_yylex(void);
@@ -37,8 +38,6 @@ extern int sensors_yylineno;
 
 static void sensors_yyerror(const char *err);
 static sensors_expr *malloc_expr(void);
-/* free_expr is defined in init.c */
-void free_expr(sensors_expr *expr);
 
 static sensors_chip *current_chip = NULL;
 
diff --git a/lib/init.c b/lib/init.c
index a06e429f..746fb67b 100644
--- a/lib/init.c
+++ b/lib/init.c
@@ -26,6 +26,7 @@
 #include "conf.h"
 #include "sysfs.h"
 #include "scanner.h"
+#include "init.h"
 
 int sensors_init(FILE *input)
 {
diff --git a/lib/init.h b/lib/init.h
new file mode 100644
index 00000000..6b7cd786
--- /dev/null
+++ b/lib/init.h
@@ -0,0 +1,27 @@
+/*
+    data.h - Part of libsensors, a Linux library for reading sensor data.
+    Copyright (C) 2007  Jean Delvare <khali@linux-fr.org>
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#ifndef LIB_SENSORS_INIT_H
+#define LIB_SENSORS_INIT_H
+
+#include "data.h"
+
+void free_expr(sensors_expr *expr);
+
+#endif /* def LIB_SENSORS_INIT_H */