diff --git a/acquire.c b/acquire.c
index 0e3f2d2..94b4e61 100644
--- a/acquire.c
+++ b/acquire.c
@@ -358,7 +358,7 @@ read_from_socket(void *anything)
   int status;
   ReceiveBuffer msg;
   struct sockaddr_in his_addr;
-  int his_addr_len;
+  socklen_t his_addr_len;
   int flags;
   int message_length;
   unsigned long remote_ip;
diff --git a/client.c b/client.c
index bcc7eb4..b7e5bcb 100644
--- a/client.c
+++ b/client.c
@@ -146,7 +146,7 @@ read_line(void)
 static unsigned long
 get_address(const char *hostname)
 {
-  unsigned char *address0;
+  char *address0;
   struct hostent *host;
   unsigned long result;
 
@@ -746,7 +746,7 @@ static int
 accheck_getaddr(char *line, unsigned long *addr)
 {
   unsigned long a, b, c, d, ip;
-  unsigned char *p, *q;
+  char *p, *q;
   p = line;
   while (*p && isspace(*p)) p++;
   if (!*p) {
@@ -1124,7 +1124,7 @@ static int
 submit_request(CMD_Request *request, CMD_Reply *reply, int *reply_auth_ok)
 {
   unsigned long tx_sequence;
-  int where_from_len;
+  socklen_t where_from_len;
   struct sockaddr_in where_from;
   int bad_length, bad_sender, bad_sequence, bad_header;
   int select_status;
diff --git a/cmdmon.c b/cmdmon.c
index c039c83..e88d7c3 100644
--- a/cmdmon.c
+++ b/cmdmon.c
@@ -1584,7 +1584,7 @@ read_from_cmd_socket(void *anything)
   CMD_Reply tx_message, *prev_tx_message;
   int rx_message_length, tx_message_length;
   struct sockaddr_in where_from;
-  int from_length;
+  socklen_t from_length;
   unsigned long remote_ip;
   unsigned short remote_port;
   int md5_ok;
diff --git a/nameserv.c b/nameserv.c
index f509dfb..e57a610 100644
--- a/nameserv.c
+++ b/nameserv.c
@@ -39,7 +39,7 @@ unsigned long
 DNS_Name2IPAddress(const char *name)
 {
   struct hostent *host;
-  unsigned char *address0;
+  char *address0;
   unsigned long result;
 
   host = gethostbyname(name);
diff --git a/ntp_core.c b/ntp_core.c
index 6c18787..f21065d 100644
--- a/ntp_core.c
+++ b/ntp_core.c
@@ -378,7 +378,7 @@ generate_packet_auth(NTP_Packet *pkt, unsigned long keyid)
   if (keyok) {
     pkt->auth_keyid = htonl(keyid);
     MD5Init(&ctx);
-    MD5Update(&ctx, keytext, keylen);
+    MD5Update(&ctx, (unsigned char *) keytext, keylen);
     MD5Update(&ctx, (unsigned char *) pkt, offsetof(NTP_Packet, auth_keyid));
     MD5Final(&ctx);
     memcpy(&(pkt->auth_data), &ctx.digest, 16);
@@ -447,7 +447,7 @@ check_packet_auth(NTP_Packet *pkt, unsigned long keyid)
   if (keyok) {
     pkt->auth_keyid = htonl(keyid);
     MD5Init(&ctx);
-    MD5Update(&ctx, keytext, keylen);
+    MD5Update(&ctx, (unsigned char *) keytext, keylen);
     MD5Update(&ctx, (unsigned char *) pkt, offsetof(NTP_Packet, auth_keyid));
     MD5Final(&ctx);
     if (!memcmp((void *) &ctx.digest, (void *) &(pkt->auth_data), 16)) {
diff --git a/ntp_io.c b/ntp_io.c
index 81b0230..fb765dd 100644
--- a/ntp_io.c
+++ b/ntp_io.c
@@ -184,7 +184,7 @@ read_from_socket(void *anything)
   ReceiveBuffer message;
   int message_length;
   struct sockaddr_in where_from;
-  int from_length;
+  socklen_t from_length;
   unsigned int flags = 0;
   struct timeval now;
   NTP_Remote_Address remote_addr;