diff --git a/src/backends/unix/network.c b/src/backends/unix/network.c
index 2c81e63a..9b198057 100644
--- a/src/backends/unix/network.c
+++ b/src/backends/unix/network.c
@@ -366,7 +366,7 @@ NET_AdrToString(netadr_t a)
 }
 
 qboolean
-NET_StringToSockaddr(char *s, struct sockaddr_storage *sadr)
+NET_StringToSockaddr(const char *s, struct sockaddr_storage *sadr)
 {
 	char copy[128];
 	char *addrs, *space;
@@ -440,7 +440,7 @@ NET_StringToSockaddr(char *s, struct sockaddr_storage *sadr)
 }
 
 qboolean
-NET_StringToAdr(char *s, netadr_t *a)
+NET_StringToAdr(const char *s, netadr_t *a)
 {
 	struct sockaddr_storage sadr;
 
diff --git a/src/backends/windows/network.c b/src/backends/windows/network.c
index 801b294a..11c255d4 100644
--- a/src/backends/windows/network.c
+++ b/src/backends/windows/network.c
@@ -385,7 +385,7 @@ NET_AdrToString(netadr_t a)
  * 192.246.40.70:28000
  */
 qboolean
-NET_StringToSockaddr(char *s, struct sockaddr_storage *sadr)
+NET_StringToSockaddr(const char *s, struct sockaddr_storage *sadr)
 {
 	char copy[128];
 	char *addrs, *space;
@@ -465,7 +465,7 @@ NET_StringToSockaddr(char *s, struct sockaddr_storage *sadr)
  * 192.246.40.70:28000
  */
 qboolean
-NET_StringToAdr(char *s, netadr_t *a)
+NET_StringToAdr(const char *s, netadr_t *a)
 {
 	struct sockaddr_storage sadr;
 
diff --git a/src/client/cl_network.c b/src/client/cl_network.c
index 3a8496f9..028de796 100644
--- a/src/client/cl_network.c
+++ b/src/client/cl_network.c
@@ -494,7 +494,7 @@ CL_PingServers_f(void)
 	int i;
 	netadr_t adr;
 	char name[32];
-	char *adrstring;
+	const char *adrstring;
 	cvar_t *noudp;
 	cvar_t *noipx;
 
@@ -530,7 +530,7 @@ CL_PingServers_f(void)
 	for (i = 0; i < 16; i++)
 	{
 		Com_sprintf(name, sizeof(name), "adr%i", i);
-		adrstring = (char *)Cvar_VariableString(name);
+		adrstring = Cvar_VariableString(name);
 
 		if (!adrstring || !adrstring[0])
 		{
diff --git a/src/client/menu/menu.c b/src/client/menu/menu.c
index 3c6b936c..f078a270 100644
--- a/src/client/menu/menu.c
+++ b/src/client/menu/menu.c
@@ -4380,6 +4380,15 @@ M_Init(void)
     Cmd_AddCommand("menu_options", M_Menu_Options_f);
     Cmd_AddCommand("menu_keys", M_Menu_Keys_f);
     Cmd_AddCommand("menu_quit", M_Menu_Quit_f);
+
+    /* initialize the server address book cvars (adr0, adr1, ...)
+     * so the entries are not lost if you don't open the address book */
+    for (int index = 0; index < NUM_ADDRESSBOOK_ENTRIES; index++)
+    {
+        char buffer[20];
+        Com_sprintf(buffer, sizeof(buffer), "adr%d", index);
+        Cvar_Get(buffer, "", CVAR_ARCHIVE);
+    }
 }
 
 void
diff --git a/src/common/header/common.h b/src/common/header/common.h
index c94fec50..a1d40749 100644
--- a/src/common/header/common.h
+++ b/src/common/header/common.h
@@ -531,7 +531,7 @@ qboolean NET_CompareAdr(netadr_t a, netadr_t b);
 qboolean NET_CompareBaseAdr(netadr_t a, netadr_t b);
 qboolean NET_IsLocalAddress(netadr_t adr);
 char *NET_AdrToString(netadr_t a);
-qboolean NET_StringToAdr(char *s, netadr_t *a);
+qboolean NET_StringToAdr(const char *s, netadr_t *a);
 void NET_Sleep(int msec);
 
 /*=================================================================== */