diff --git a/vl.c b/vl.c
index 6c4a509..d82c3d8 100644
--- a/vl.c
+++ b/vl.c
@@ -1835,7 +1835,7 @@
     return NULL;
 }
 
-DriveInfo *drive_get_by_id(char *id)
+DriveInfo *drive_get_by_id(const char *id)
 {
     DriveInfo *dinfo;