diff --git a/cansend.c b/cansend.c
index 72d7016..51d9689 100644
--- a/cansend.c
+++ b/cansend.c
@@ -56,7 +56,7 @@
 
 #include "lib.h"
 
-void print_usage(char *prg)
+static void print_usage(char *prg)
 {
 	fprintf(stderr, "%s - send CAN-frames via CAN_RAW sockets.\n", prg);
 	fprintf(stderr, "\nUsage: %s <device> <can_frame>.\n", prg);
@@ -147,10 +147,12 @@ int main(int argc, char **argv)
 		frame.len = can_fd_dlc2len(can_fd_len2dlc(frame.len));
 	}
 
-	/* disable default receive filter on this RAW socket */
-	/* This is obsolete as we do not read from the socket at all, but for */
-	/* this reason we can remove the receive list in the Kernel to save a */
-	/* little (really a very little!) CPU usage.                          */
+	/*
+	 * disable default receive filter on this RAW socket This is
+	 * obsolete as we do not read from the socket at all, but for
+	 * this reason we can remove the receive list in the Kernel to
+	 * save a little (really a very little!) CPU usage.
+	 */
 	setsockopt(s, SOL_CAN_RAW, CAN_RAW_FILTER, NULL, 0);
 
 	if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0) {