diff --git a/tools/hcidump.c b/tools/hcidump.c
index a14a784..8e5f663 100644
--- a/tools/hcidump.c
+++ b/tools/hcidump.c
@@ -743,7 +743,8 @@ static int wait_connection(char *addr, char *port)
 	struct addrinfo *ai, *runp;
 	struct addrinfo hints;
 	struct pollfd fds[3];
-	int err, opt, datagram, nfds = 0;
+	unsigned int nfds = 0;
+	int err, opt, datagram;
 
 	memset(&hints, 0, sizeof (hints));
 	hints.ai_flags = AI_PASSIVE | AI_ADDRCONFIG;
@@ -815,7 +816,8 @@ static int wait_connection(char *addr, char *port)
 	freeaddrinfo(ai);
 
 	while (1) {
-		int i, n = poll(fds, nfds, -1);
+		unsigned int i;
+		int n = poll(fds, nfds, -1);
 		if (n <= 0)
 			continue;
 
@@ -844,7 +846,7 @@ static int wait_connection(char *addr, char *port)
 			printf("client: %s:%s snap_len: %d filter: 0x%lx\n",
 					hname, hport, snap_len, parser.filter);
 
-			for (n = 0; n < nfds; n++)
+			for (n = 0; n < (int) nfds; n++)
 				close(fds[n].fd);
 
 			return sk;
diff --git a/tools/parser/csr.c b/tools/parser/csr.c
index 6cce85b..89ea882 100644
--- a/tools/parser/csr.c
+++ b/tools/parser/csr.c
@@ -146,7 +146,7 @@ static inline void features_dump(int level, char *str, struct frame *frm)
 static inline void commands_dump(int level, char *str, struct frame *frm)
 {
 	unsigned char commands[64];
-	int i;
+	unsigned int i;
 
 	memcpy(commands, frm->ptr, frm->len);
 
diff --git a/tools/parser/l2cap.c b/tools/parser/l2cap.c
index a906f42..2153719 100644
--- a/tools/parser/l2cap.c
+++ b/tools/parser/l2cap.c
@@ -899,7 +899,7 @@ void l2cap_dump(int level, struct frame *frm)
 		hdr  = frm->ptr;
 		dlen = btohs(hdr->len);
 
-		if (frm->len == (dlen + L2CAP_HDR_SIZE)) {
+		if ((int) frm->len == (dlen + L2CAP_HDR_SIZE)) {
 			/* Complete frame */
 			l2cap_parse(level, frm);
 			return;
diff --git a/tools/parser/obex.c b/tools/parser/obex.c
index 0f68443..97ce2af 100644
--- a/tools/parser/obex.c
+++ b/tools/parser/obex.c
@@ -241,7 +241,7 @@ void obex_dump(int level, struct frame *frm)
 		length = get_u16(frm);
 		status = opcode & 0x7f;
 
-		if (frm->len < length - 3) {
+		if ((int) frm->len < length - 3) {
 			frm->ptr -= 3;
 			frm->len += 3;
 			return;
diff --git a/tools/parser/parser.c b/tools/parser/parser.c
index e50590e..2df2bf9 100644
--- a/tools/parser/parser.c
+++ b/tools/parser/parser.c
@@ -254,7 +254,7 @@ void ascii_dump(int level, struct frame *frm, int num)
 	unsigned char *buf = frm->ptr;
 	register int i, n;
 
-	if ((num < 0) || (num > frm->len))
+	if ((num < 0) || (num > (int) frm->len))
 		num = frm->len;
 
 	for (i = 0, n = 1; i < num; i++, n++) {
@@ -275,7 +275,7 @@ void hex_dump(int level, struct frame *frm, int num)
 	unsigned char *buf = frm->ptr;
 	register int i, n;
 
-	if ((num < 0) || (num > frm->len))
+	if ((num < 0) || (num > (int) frm->len))
 		num = frm->len;
 
 	for (i = 0, n = 1; i < num; i++, n++) {
@@ -296,7 +296,7 @@ void ext_dump(int level, struct frame *frm, int num)
 	unsigned char *buf = frm->ptr;
 	register int i, n = 0, size;
 
-	if ((num < 0) || (num > frm->len))
+	if ((num < 0) || (num > (int) frm->len))
 		num = frm->len;
 
 	while (num > 0) {
diff --git a/tools/parser/ppp.c b/tools/parser/ppp.c
index 6ef24e9..530a4b9 100644
--- a/tools/parser/ppp.c
+++ b/tools/parser/ppp.c
@@ -46,7 +46,7 @@ static unsigned char ppp_magic3[] = { 0x7e, 0x7d, 0xdf, 0x7d, 0x23, 0xc0, 0x21 }
 
 static inline int check_for_ppp_traffic(unsigned char *data, int size)
 {
-	int i;
+	unsigned int i;
 
 	for (i = 0; i < size - sizeof(ppp_magic1); i++)
 		if (!memcmp(data + i, ppp_magic1, sizeof(ppp_magic1))) {
diff --git a/tools/parser/rfcomm.c b/tools/parser/rfcomm.c
index b85df91..7c66049 100644
--- a/tools/parser/rfcomm.c
+++ b/tools/parser/rfcomm.c
@@ -93,7 +93,7 @@ static inline void mcc_fcoff(int level, uint8_t *ptr, int len,
 	print_mcc(mcc_head);
 }
 
-static inline void mcc_msc(int level, uint8_t *ptr, int len,
+static inline void mcc_msc(int level, uint8_t *ptr, unsigned int len,
 				long_frame_head *head, mcc_long_frame_head *mcc_head)
 {
 	msc_msg *msc = (void*) (ptr - STRUCT_END(msc_msg, mcc_s_head));
@@ -116,7 +116,7 @@ static inline void mcc_msc(int level, uint8_t *ptr, int len,
 		printf("\n");
 }
 
-static inline void mcc_rpn(int level, uint8_t *ptr, int len,
+static inline void mcc_rpn(int level, uint8_t *ptr, unsigned int len,
 				long_frame_head *head, mcc_long_frame_head *mcc_head)
 {
 	rpn_msg *rpn = (void *) (ptr - STRUCT_END(rpn_msg, mcc_s_head));
diff --git a/tools/parser/sdp.c b/tools/parser/sdp.c
index f0ffea3..7ccf07b 100644
--- a/tools/parser/sdp.c
+++ b/tools/parser/sdp.c
@@ -222,7 +222,7 @@ static sdp_attr_id_nam_lookup_table_t sdp_attr_id_nam_lookup_table[] = {
 
 char* get_uuid_name(int uuid)
 {
-	int i;
+	unsigned int i;
 
 	for (i = 0; i < SDP_UUID_NAM_LOOKUP_TABLE_SIZE; i++) {
 		if (sdp_uuid_nam_lookup_table[i].uuid == uuid)
@@ -234,7 +234,7 @@ char* get_uuid_name(int uuid)
 
 static inline char* get_attr_id_name(int attr_id)
 {
-	int i;
+	unsigned int i;
 
 	for (i = 0; i < SDP_ATTR_ID_NAM_LOOKUP_TABLE_SIZE; i++)
 		if (sdp_attr_id_nam_lookup_table[i].attr_id == attr_id)
@@ -399,7 +399,7 @@ static inline void print_de(int, struct frame *frm, int *split, uint16_t *psm, u
 static inline void print_des(uint8_t de_type, int level, int n, struct frame *frm, int *split, uint16_t *psm, uint8_t *channel)
 {
 	int len = frm->len;
-	while (len - frm->len < n && frm->len > 0)
+	while (len - (int) frm->len < n && (int) frm->len > 0)
 		print_de(level, frm, split, psm, channel);
 }
 
@@ -455,7 +455,7 @@ static inline void print_srv_srch_pat(int level, struct frame *frm)
 
 	if (parse_de_hdr(frm, &n1) == SDP_DE_SEQ) {
 		len = frm->len;
-		while (len - frm->len < n1 && frm->len > 0) {
+		while (len - (int) frm->len < n1 && (int) frm->len > 0) {
 			if (parse_de_hdr(frm, &n2) == SDP_DE_UUID) {
 				print_uuid(n2, frm, NULL, NULL);
 			} else {
@@ -481,7 +481,7 @@ static inline void print_attr_id_list(int level, struct frame *frm)
 
 	if (parse_de_hdr(frm, &n1) == SDP_DE_SEQ) {
 		len = frm->len;
-		while (len - frm->len < n1 && frm->len > 0) {
+		while (len - (int) frm->len < n1 && (int) frm->len > 0) {
 			/* Print AttributeID */
 			if (parse_de_hdr(frm, &n2) == SDP_DE_UINT) {
 				char *name;
@@ -520,7 +520,7 @@ static inline void print_attr_list(int level, struct frame *frm)
 
 	if (parse_de_hdr(frm, &n1) == SDP_DE_SEQ) {
 		len = frm->len;
-		while (len - frm->len < n1 && frm->len > 0) {
+		while (len - (int) frm->len < n1 && (int) frm->len > 0) {
 			/* Print AttributeID */
 			if (parse_de_hdr(frm, &n2) == SDP_DE_UINT && n2 == sizeof(attr_id)) {
 				char *name;
@@ -558,7 +558,7 @@ static inline void print_attr_lists(int level, struct frame *frm)
 	int count = frm->len;
 
 	if (parse_de_hdr(frm, &n) == SDP_DE_SEQ) {
-		while (count - frm->len < n && frm->len > 0) {
+		while (count - (int) frm->len < n && (int) frm->len > 0) {
 			p_indent(level, 0);
 			printf("record #%d\n", cnt++);
 			print_attr_list(level + 2, frm);