--- a/configure.ac
+++ b/configure.ac
@@ -21,7 +21,7 @@
 # Checks for library functions.
 AC_FUNC_MKTIME
 AC_FUNC_STAT
-AC_CHECK_FUNCS([atexit memset strstr])
+AC_CHECK_FUNCS([atexit memset strstr strlen strcpy strcmp strcat memcpy])
 
 AC_OUTPUT([Makefile src/Makefile vformat/Makefile test/Makefile doc/Makefile])
 #AC_CONFIG_FILES([])
--- a/src/vf_config.h
+++ b/src/vf_config.h
@@ -31,6 +31,8 @@
  * 
  *******************************************************************************/
 
+#include <config.h>
+
 #ifndef _VF_CONFIG_H_
 #define _VF_CONFIG_H_