diff --git a/config.c b/config.c
index 152fa282f0..34584f62b4 100644
--- a/config.c
+++ b/config.c
@@ -11,7 +11,7 @@
 #define MAXNAME (256)
 
 static FILE *config_file;
-static char *config_file_name;
+static const char *config_file_name;
 static int config_linenr;
 static int get_next_char(void)
 {