make _change_device() call take a const string

1 files changed, 1 insertions, 1 deletions

diff --git a/src/null.c b/src/null.c
index 683550e..da91e44 100644
--- a/src/null.c
+++ b/src/null.c
@@ -41,7 +41,7 @@ int driver_destroy(ca_context *c) {
     return CA_SUCCESS;
 }
 
-int driver_change_device(ca_context *c, char *device) {
+int driver_change_device(ca_context *c, const char *device) {
     ca_return_val_if_fail(c, CA_ERROR_INVALID);
 
     return CA_SUCCESS;