diff --git a/chap02/time_server.c b/chap02/time_server.c
index b3456cb..3233ec5 100644
--- a/chap02/time_server.c
+++ b/chap02/time_server.c
@@ -130,7 +130,7 @@ int main() {
 
     printf("Reading request...\n");
     char request[1024];
-    int bytes_received = recv(socket_client, request, 1024, 0);
+    int bytes_received = recv(socket_client, request, sizeof(request), 0);
     printf("Received %d bytes.\n", bytes_received);
     //printf("%.*s", bytes_received, request);
 
diff --git a/chap02/time_server_dual.c b/chap02/time_server_dual.c
index e40e1a2..72c5b2c 100644
--- a/chap02/time_server_dual.c
+++ b/chap02/time_server_dual.c
@@ -139,7 +139,7 @@ int main() {
 
     printf("Reading request...\n");
     char request[1024];
-    int bytes_received = recv(socket_client, request, 1024, 0);
+    int bytes_received = recv(socket_client, request, sizeof(request), 0);
     printf("Received %d bytes.\n", bytes_received);
     //printf("%.*s", bytes_received, request);
 
diff --git a/chap02/time_server_ipv6.c b/chap02/time_server_ipv6.c
index ea74b66..e41812f 100644
--- a/chap02/time_server_ipv6.c
+++ b/chap02/time_server_ipv6.c
@@ -130,7 +130,7 @@ int main() {
 
     printf("Reading request...\n");
     char request[1024];
-    int bytes_received = recv(socket_client, request, 1024, 0);
+    int bytes_received = recv(socket_client, request, sizeof(request), 0);
     printf("Received %d bytes.\n", bytes_received);
     //printf("%.*s", bytes_received, request);
 
diff --git a/chap03/tcp_client.c b/chap03/tcp_client.c
index e000939..5d22e4f 100644
--- a/chap03/tcp_client.c
+++ b/chap03/tcp_client.c
@@ -105,7 +105,7 @@ int main(int argc, char *argv[]) {
 
         if (FD_ISSET(socket_peer, &reads)) {
             char read[4096];
-            int bytes_received = recv(socket_peer, read, 4096, 0);
+            int bytes_received = recv(socket_peer, read, sizeof(read), 0);
             if (bytes_received < 1) {
                 printf("Connection closed by peer.\n");
                 break;
@@ -120,7 +120,7 @@ int main(int argc, char *argv[]) {
         if(FD_ISSET(0, &reads)) {
 #endif
             char read[4096];
-            if (!fgets(read, 4096, stdin)) break;
+            if (!fgets(read, sizeof(read), stdin)) break;
             printf("Sending: %s", read);
             int bytes_sent = send(socket_peer, read, strlen(read), 0);
             printf("Sent %d bytes.\n", bytes_sent);
diff --git a/chap03/tcp_serve_chat.c b/chap03/tcp_serve_chat.c
index fdc54e7..3149000 100644
--- a/chap03/tcp_serve_chat.c
+++ b/chap03/tcp_serve_chat.c
@@ -117,7 +117,7 @@ int main() {
 
                 } else {
                     char read[1024];
-                    int bytes_received = recv(i, read, 1024, 0);
+                    int bytes_received = recv(i, read, sizeof(read), 0);
                     if (bytes_received < 1) {
                         FD_CLR(i, &master);
                         CLOSESOCKET(i);
diff --git a/chap03/tcp_serve_toupper.c b/chap03/tcp_serve_toupper.c
index 240afc1..d9479b2 100644
--- a/chap03/tcp_serve_toupper.c
+++ b/chap03/tcp_serve_toupper.c
@@ -117,7 +117,7 @@ int main() {
 
                 } else {
                     char read[1024];
-                    int bytes_received = recv(i, read, 1024, 0);
+                    int bytes_received = recv(i, read, sizeof(read), 0);
                     if (bytes_received < 1) {
                         FD_CLR(i, &master);
                         CLOSESOCKET(i);
diff --git a/chap03/tcp_serve_toupper_fork.c b/chap03/tcp_serve_toupper_fork.c
index 13709c7..876ea5f 100644
--- a/chap03/tcp_serve_toupper_fork.c
+++ b/chap03/tcp_serve_toupper_fork.c
@@ -94,7 +94,7 @@ int main() {
             CLOSESOCKET(socket_listen);
             while(1) {
                 char read[1024];
-                int bytes_received = recv(socket_client, read, 1024, 0);
+                int bytes_received = recv(socket_client, read, sizeof(read), 0);
                 if (bytes_received < 1) {
                     CLOSESOCKET(socket_client);
                     exit(0);
diff --git a/chap04/udp_client.c b/chap04/udp_client.c
index e628b9a..46a92da 100644
--- a/chap04/udp_client.c
+++ b/chap04/udp_client.c
@@ -105,7 +105,7 @@ int main(int argc, char *argv[]) {
 
         if (FD_ISSET(socket_peer, &reads)) {
             char read[4096];
-            int bytes_received = recv(socket_peer, read, 4096, 0);
+            int bytes_received = recv(socket_peer, read, sizeof(read), 0);
             if (bytes_received < 1) {
                 printf("Connection closed by peer.\n");
                 break;
@@ -120,7 +120,7 @@ int main(int argc, char *argv[]) {
         if(FD_ISSET(0, &reads)) {
 #endif
             char read[4096];
-            if (!fgets(read, 4096, stdin)) break;
+            if (!fgets(read, sizeof(read), stdin)) break;
             printf("Sending: %s", read);
             int bytes_sent = send(socket_peer, read, strlen(read), 0);
             printf("Sent %d bytes.\n", bytes_sent);
diff --git a/chap04/udp_recvfrom.c b/chap04/udp_recvfrom.c
index 73ba095..c240efb 100644
--- a/chap04/udp_recvfrom.c
+++ b/chap04/udp_recvfrom.c
@@ -68,7 +68,7 @@ int main() {
     socklen_t client_len = sizeof(client_address);
     char read[1024];
     int bytes_received = recvfrom(socket_listen,
-            read, 1024,
+            read, sizeof(read),
             0,
             (struct sockaddr*) &client_address, &client_len);
 
diff --git a/chap04/udp_serve_toupper.c b/chap04/udp_serve_toupper.c
index 2c7464e..e3e542e 100644
--- a/chap04/udp_serve_toupper.c
+++ b/chap04/udp_serve_toupper.c
@@ -86,7 +86,7 @@ int main() {
             socklen_t client_len = sizeof(client_address);
 
             char read[1024];
-            int bytes_received = recvfrom(socket_listen, read, 1024, 0,
+            int bytes_received = recvfrom(socket_listen, read, sizeof(read), 0,
                     (struct sockaddr *)&client_address, &client_len);
             if (bytes_received < 1) {
                 fprintf(stderr, "connection closed. (%d)\n",
diff --git a/chap04/udp_serve_toupper_simple.c b/chap04/udp_serve_toupper_simple.c
index b4fabd4..d078245 100644
--- a/chap04/udp_serve_toupper_simple.c
+++ b/chap04/udp_serve_toupper_simple.c
@@ -73,7 +73,7 @@ int main() {
         socklen_t client_len = sizeof(client_address);
 
         char read[1024];
-        int bytes_received = recvfrom(socket_listen, read, 1024, 0,
+        int bytes_received = recvfrom(socket_listen, read, sizeof(read), 0,
                 (struct sockaddr *)&client_address, &client_len);
         if (bytes_received < 1) {
             fprintf(stderr, "connection closed. (%d)\n",
diff --git a/chap05/dns_query.c b/chap05/dns_query.c
index 56cc4bb..d029115 100644
--- a/chap05/dns_query.c
+++ b/chap05/dns_query.c
@@ -321,7 +321,7 @@ int main(int argc, char *argv[]) {
 
     char read[1024];
     int bytes_received = recvfrom(socket_peer,
-            read, 1024, 0, 0, 0);
+            read, sizeof(read), 0, 0, 0);
 
     printf("Received %d bytes.\n", bytes_received);
 
diff --git a/chap08/smtp_send.c b/chap08/smtp_send.c
index 3ef8a7f..fe517e6 100644
--- a/chap08/smtp_send.c
+++ b/chap08/smtp_send.c
@@ -209,7 +209,7 @@ int main() {
     timeinfo = gmtime(&timer);
 
     char date[128];
-    strftime(date, 128, "%a, %d %b %Y %H:%M:%S +0000", timeinfo);
+    strftime(date, sizeof(date), "%a, %d %b %Y %H:%M:%S +0000", timeinfo);
 
     send_format(server, "Date:%s\r\n", date);
 
diff --git a/chap09/tls_client.c b/chap09/tls_client.c
index 642bc19..b9969f2 100644
--- a/chap09/tls_client.c
+++ b/chap09/tls_client.c
@@ -167,7 +167,7 @@ int main(int argc, char *argv[]) {
 
         if (FD_ISSET(socket_peer, &reads)) {
             char read[4096];
-            int bytes_received = SSL_read(ssl, read, 4096);
+            int bytes_received = SSL_read(ssl, read, sizeof(read));
             if (bytes_received < 1) {
                 int err;
                 if ((err = SSL_get_error(ssl, bytes_received)) &&
@@ -189,7 +189,7 @@ int main(int argc, char *argv[]) {
         if(FD_ISSET(0, &reads)) {
 #endif
             char read[4096];
-            if (!fgets(read, 4096, stdin)) break;
+            if (!fgets(read, sizeof(read), stdin)) break;
             printf("Sending: %s", read);
             int bytes_sent = SSL_write(ssl, read, strlen(read));
             printf("Sent %d bytes.\n", bytes_sent);
diff --git a/chap10/tls_time_server.c b/chap10/tls_time_server.c
index bf88124..846ac2b 100644
--- a/chap10/tls_time_server.c
+++ b/chap10/tls_time_server.c
@@ -135,7 +135,7 @@ int main() {
 
         printf("Reading request...\n");
         char request[1024];
-        int bytes_received = SSL_read(ssl, request, 1024);
+        int bytes_received = SSL_read(ssl, request, sizeof(request));
         printf("Received %d bytes.\n", bytes_received);
         //printf("%.*s", bytes_received, request);
 
diff --git a/chap13/error_text.c b/chap13/error_text.c
index 6432ff1..0410d88 100644
--- a/chap13/error_text.c
+++ b/chap13/error_text.c
@@ -32,7 +32,7 @@ const char *get_error_text() {
     static char message[256] = {0};
     FormatMessage(
         FORMAT_MESSAGE_FROM_SYSTEM|FORMAT_MESSAGE_IGNORE_INSERTS,
-        0, WSAGetLastError(), 0, message, 256, 0);
+        0, WSAGetLastError(), 0, message, sizeof(message), 0);
     char *nl = strrchr(message, '\n');
     if (nl) *nl = 0;
     return message;
diff --git a/chap13/server_crash.c b/chap13/server_crash.c
index 1156ac1..0dc0c01 100644
--- a/chap13/server_crash.c
+++ b/chap13/server_crash.c
@@ -93,7 +93,7 @@ int main() {
     int bytes_received;
     while(1) {
         char read[1024];
-        bytes_received = recv(socket_client, read, 1024, 0);
+        bytes_received = recv(socket_client, read, sizeof(read), 0);
         if (bytes_received < 1) {
             break;
         } else {