diff --git a/archival/dpkg.c b/archival/dpkg.c
index c096518a2..d3b56e398 100644
--- a/archival/dpkg.c
+++ b/archival/dpkg.c
@@ -1327,7 +1327,7 @@ void free_array(char **array)
  * the status_hashtable to retrieve the info. This results in smaller code than
  * scanning the status file. The resulting list, however, is unsorted.
  */
-void list_packages(void)
+static void list_packages(void)
 {
         int i;
 
diff --git a/archival/gzip.c b/archival/gzip.c
index 0c104cfc6..6cf4b395e 100644
--- a/archival/gzip.c
+++ b/archival/gzip.c
@@ -541,7 +541,7 @@ static unsigned bi_reverse(unsigned code, int len)
 /* ===========================================================================
  * Write out any remaining bits in an incomplete byte.
  */
-static void bi_windup()
+static void bi_windup(void)
 {
 	if (bi_valid > 8) {
 		put_short(bi_buf);
@@ -978,7 +978,7 @@ static void check_match(IPos start, IPos match, int length)
  *    file reads are performed for at least two bytes (required for the
  *    translate_eol option).
  */
-static void fill_window()
+static void fill_window(void)
 {
 	register unsigned n, m;
 	unsigned more =
@@ -1042,7 +1042,7 @@ static void fill_window()
  * evaluation for matches: a match is finally adopted only if there is
  * no better match at the next window position.
  */
-static ulg deflate()
+static ulg deflate(void)
 {
 	IPos hash_head;		/* head of hash chain */
 	IPos prev_match;	/* previous match */
@@ -1730,7 +1730,7 @@ static void ct_init(ush * attr, int *methodp)
 /* ===========================================================================
  * Initialize a new block.
  */
-static void init_block()
+static void init_block(void)
 {
 	int n;				/* iterates over tree elements */
 
@@ -2143,7 +2143,7 @@ static void send_tree(ct_data * tree, int max_code)
  * Construct the Huffman tree for the bit lengths and return the index in
  * bl_order of the last bit length code to send.
  */
-static int build_bl_tree()
+static int build_bl_tree(void)
 {
 	int max_blindex;	/* index of last bit length code of non zero freq */
 
@@ -2406,7 +2406,7 @@ static void compress_block(ct_data * ltree, ct_data * dtree)
  * IN assertion: the fields freq of dyn_ltree are set and the total of all
  * frequencies does not exceed 64K (to fit in an int on 16 bit machines).
  */
-static void set_file_type()
+static void set_file_type(void)
 {
 	int n = 0;
 	unsigned ascii_freq = 0;
@@ -2519,7 +2519,7 @@ static int file_read(char *buf, unsigned size)
  * Write the output buffer outbuf[0..outcnt-1] and update bytes_out.
  * (used for the compressed data only)
  */
-static void flush_outbuf()
+static void flush_outbuf(void)
 {
 	if (outcnt == 0)
 		return;
diff --git a/coreutils/test.c b/coreutils/test.c
index cec3c471d..3da2daecd 100644
--- a/coreutils/test.c
+++ b/coreutils/test.c
@@ -310,7 +310,7 @@ static arith_t primary(enum token n)
 	return strlen(*t_wp) > 0;
 }
 
-static int binop()
+static int binop(void)
 {
 	const char *opnd1, *opnd2;
 	struct t_op const *op;
@@ -537,7 +537,7 @@ static int test_eaccess(char *path, int mode)
 	return (-1);
 }
 
-static void initialize_group_array()
+static void initialize_group_array(void)
 {
 	ngroups = getgroups(0, NULL);
 	group_array = xrealloc(group_array, ngroups * sizeof(gid_t));
diff --git a/editors/vi.c b/editors/vi.c
index cd6cf0ea1..5a47f5a23 100644
--- a/editors/vi.c
+++ b/editors/vi.c
@@ -2340,7 +2340,7 @@ static Byte readit(void)	// read (maybe cursor) key from stdin
 }
 
 //----- IO Routines --------------------------------------------
-static Byte get_one_char()
+static Byte get_one_char(void)
 {
 	static Byte c;
 
@@ -2600,25 +2600,25 @@ static void place_cursor(int row, int col, int opti)
 }
 
 //----- Erase from cursor to end of line -----------------------
-static void clear_to_eol()
+static void clear_to_eol(void)
 {
 	write1(Ceol);   // Erase from cursor to end of line
 }
 
 //----- Erase from cursor to end of screen -----------------------
-static void clear_to_eos()
+static void clear_to_eos(void)
 {
 	write1(Ceos);   // Erase from cursor to end of screen
 }
 
 //----- Start standout mode ------------------------------------
-static void standout_start() // send "start reverse video" sequence
+static void standout_start(void) // send "start reverse video" sequence
 {
 	write1(SOs);     // Start reverse video mode
 }
 
 //----- End standout mode --------------------------------------
-static void standout_end() // send "end reverse video" sequence
+static void standout_end(void) // send "end reverse video" sequence
 {
 	write1(SOn);     // End reverse video mode
 }
@@ -2648,7 +2648,7 @@ static void Indicate_Error(void)
 
 //----- Screen[] Routines --------------------------------------
 //----- Erase the Screen[] memory ------------------------------
-static void screen_erase()
+static void screen_erase(void)
 {
 	memset(screen, ' ', screensize);	// clear new screen
 }
diff --git a/loginutils/login.c b/loginutils/login.c
index f3630f102..25f3c01e2 100644
--- a/loginutils/login.c
+++ b/loginutils/login.c
@@ -387,7 +387,7 @@ static int is_my_tty ( const char *tty )
 }
 
 
-static void motd ( )
+static void motd (void)
 {
 	FILE *fp;
 	register int c;
diff --git a/networking/libiproute/utils.c b/networking/libiproute/utils.c
index fa1548609..d86d4f8f5 100644
--- a/networking/libiproute/utils.c
+++ b/networking/libiproute/utils.c
@@ -238,7 +238,7 @@ __u32 get_addr32(char *name)
 	return addr.data[0];
 }
 
-void incomplete_command()
+void incomplete_command(void)
 {
 	bb_error_msg("Command line is not complete. Try option \"help\"");
 	exit(-1);