diff --git a/tests/server/util.c b/tests/server/util.c
index 74d5dcdfe..3fea37c46 100644
--- a/tests/server/util.c
+++ b/tests/server/util.c
@@ -66,7 +66,7 @@ int ourerrno(void)
 }
 
 /* someone else must set this properly */
-extern char *serverlogfile;
+extern const char *serverlogfile;
 
 void logmsg(const char *msg, ...)
 {