diff --git a/drivers/media/firewire/firedtv-avc.c b/drivers/media/firewire/firedtv-avc.c
index 1c933b2cf760..3ef5df1648d7 100644
--- a/drivers/media/firewire/firedtv-avc.c
+++ b/drivers/media/firewire/firedtv-avc.c
@@ -968,7 +968,8 @@ static int get_ca_object_length(struct avc_response_frame *r)
 	return r->operand[7];
 }
 
-int avc_ca_app_info(struct firedtv *fdtv, char *app_info, unsigned int *len)
+int avc_ca_app_info(struct firedtv *fdtv, unsigned char *app_info,
+		    unsigned int *len)
 {
 	struct avc_command_frame *c = (void *)fdtv->avc_data;
 	struct avc_response_frame *r = (void *)fdtv->avc_data;
@@ -1009,7 +1010,8 @@ int avc_ca_app_info(struct firedtv *fdtv, char *app_info, unsigned int *len)
 	return ret;
 }
 
-int avc_ca_info(struct firedtv *fdtv, char *app_info, unsigned int *len)
+int avc_ca_info(struct firedtv *fdtv, unsigned char *app_info,
+		unsigned int *len)
 {
 	struct avc_command_frame *c = (void *)fdtv->avc_data;
 	struct avc_response_frame *r = (void *)fdtv->avc_data;
diff --git a/drivers/media/firewire/firedtv.h b/drivers/media/firewire/firedtv.h
index 876cdec8329b..009905a19947 100644
--- a/drivers/media/firewire/firedtv.h
+++ b/drivers/media/firewire/firedtv.h
@@ -124,8 +124,10 @@ int avc_lnb_control(struct firedtv *fdtv, char voltage, char burst,
 		    struct dvb_diseqc_master_cmd *diseqcmd);
 void avc_remote_ctrl_work(struct work_struct *work);
 int avc_register_remote_control(struct firedtv *fdtv);
-int avc_ca_app_info(struct firedtv *fdtv, char *app_info, unsigned int *len);
-int avc_ca_info(struct firedtv *fdtv, char *app_info, unsigned int *len);
+int avc_ca_app_info(struct firedtv *fdtv, unsigned char *app_info,
+		    unsigned int *len);
+int avc_ca_info(struct firedtv *fdtv, unsigned char *app_info,
+		unsigned int *len);
 int avc_ca_reset(struct firedtv *fdtv);
 int avc_ca_pmt(struct firedtv *fdtv, char *app_info, int length);
 int avc_ca_get_time_date(struct firedtv *fdtv, int *interval);