diff --git a/hiredis.c b/hiredis.c
index 80599db..9b74b5b 100644
--- a/hiredis.c
+++ b/hiredis.c
@@ -1025,7 +1025,7 @@ redisContext *redisConnect(const char *ip, int port) {
     return c;
 }
 
-redisContext *redisConnectWithTimeout(const char *ip, int port, struct timeval tv) {
+redisContext *redisConnectWithTimeout(const char *ip, int port, const struct timeval tv) {
     redisContext *c;
 
     c = redisContextInit();
@@ -1061,7 +1061,7 @@ redisContext *redisConnectUnix(const char *path) {
     return c;
 }
 
-redisContext *redisConnectUnixWithTimeout(const char *path, struct timeval tv) {
+redisContext *redisConnectUnixWithTimeout(const char *path, const struct timeval tv) {
     redisContext *c;
 
     c = redisContextInit();
@@ -1086,7 +1086,7 @@ redisContext *redisConnectUnixNonBlock(const char *path) {
 }
 
 /* Set read/write timeout on a blocking socket. */
-int redisSetTimeout(redisContext *c, struct timeval tv) {
+int redisSetTimeout(redisContext *c, const struct timeval tv) {
     if (c->flags & REDIS_BLOCK)
         return redisContextSetTimeout(c,tv);
     return REDIS_ERR;
diff --git a/hiredis.h b/hiredis.h
index 42290a1..c65098b 100644
--- a/hiredis.h
+++ b/hiredis.h
@@ -173,12 +173,12 @@ typedef struct redisContext {
 } redisContext;
 
 redisContext *redisConnect(const char *ip, int port);
-redisContext *redisConnectWithTimeout(const char *ip, int port, struct timeval tv);
+redisContext *redisConnectWithTimeout(const char *ip, int port, const struct timeval tv);
 redisContext *redisConnectNonBlock(const char *ip, int port);
 redisContext *redisConnectUnix(const char *path);
-redisContext *redisConnectUnixWithTimeout(const char *path, struct timeval tv);
+redisContext *redisConnectUnixWithTimeout(const char *path, const struct timeval tv);
 redisContext *redisConnectUnixNonBlock(const char *path);
-int redisSetTimeout(redisContext *c, struct timeval tv);
+int redisSetTimeout(redisContext *c, const struct timeval tv);
 int redisEnableKeepAlive(redisContext *c);
 void redisFree(redisContext *c);
 int redisBufferRead(redisContext *c);
diff --git a/net.c b/net.c
index 96ca63d..483b160 100644
--- a/net.c
+++ b/net.c
@@ -232,7 +232,7 @@ int redisCheckSocketError(redisContext *c, int fd) {
     return REDIS_OK;
 }
 
-int redisContextSetTimeout(redisContext *c, struct timeval tv) {
+int redisContextSetTimeout(redisContext *c, const struct timeval tv) {
     if (setsockopt(c->fd,SOL_SOCKET,SO_RCVTIMEO,&tv,sizeof(tv)) == -1) {
         __redisSetErrorFromErrno(c,REDIS_ERR_IO,"setsockopt(SO_RCVTIMEO)");
         return REDIS_ERR;
@@ -244,7 +244,7 @@ int redisContextSetTimeout(redisContext *c, struct timeval tv) {
     return REDIS_OK;
 }
 
-int redisContextConnectTcp(redisContext *c, const char *addr, int port, struct timeval *timeout) {
+int redisContextConnectTcp(redisContext *c, const char *addr, int port, const struct timeval *timeout) {
     int s, rv;
     char _port[6];  /* strlen("65535"); */
     struct addrinfo hints, *servinfo, *p;
@@ -300,7 +300,7 @@ end:
     return rv;  // Need to return REDIS_OK if alright
 }
 
-int redisContextConnectUnix(redisContext *c, const char *path, struct timeval *timeout) {
+int redisContextConnectUnix(redisContext *c, const char *path, const struct timeval *timeout) {
     int s;
     int blocking = (c->flags & REDIS_BLOCK);
     struct sockaddr_un sa;
diff --git a/net.h b/net.h
index 36096fe..94b76f5 100644
--- a/net.h
+++ b/net.h
@@ -40,9 +40,9 @@
 #endif
 
 int redisCheckSocketError(redisContext *c, int fd);
-int redisContextSetTimeout(redisContext *c, struct timeval tv);
-int redisContextConnectTcp(redisContext *c, const char *addr, int port, struct timeval *timeout);
-int redisContextConnectUnix(redisContext *c, const char *path, struct timeval *timeout);
+int redisContextSetTimeout(redisContext *c, const struct timeval tv);
+int redisContextConnectTcp(redisContext *c, const char *addr, int port, const struct timeval *timeout);
+int redisContextConnectUnix(redisContext *c, const char *path, const struct timeval *timeout);
 int redisKeepAlive(redisContext *c, int interval);
 
 #endif