diff --git a/src/net_defs.h b/src/net_defs.h
index e88615dc..bf6a264e 100644
--- a/src/net_defs.h
+++ b/src/net_defs.h
@@ -87,7 +87,7 @@ struct _net_module_s
 
     // Try to resolve a name to an address
 
-    net_addr_t *(*ResolveAddress)(char *addr);
+    net_addr_t *(*ResolveAddress)(const char *addr);
 };
 
 // net_addr_t
diff --git a/src/net_loop.c b/src/net_loop.c
index 8ec63e88..65140fa3 100644
--- a/src/net_loop.c
+++ b/src/net_loop.c
@@ -128,7 +128,7 @@ static void NET_CL_FreeAddress(net_addr_t *addr)
 {
 }
 
-static net_addr_t *NET_CL_ResolveAddress(char *address)
+static net_addr_t *NET_CL_ResolveAddress(const char *address)
 {
     if (address == NULL)
     {
@@ -204,7 +204,7 @@ static void NET_SV_FreeAddress(net_addr_t *addr)
 {
 }
 
-static net_addr_t *NET_SV_ResolveAddress(char *address)
+static net_addr_t *NET_SV_ResolveAddress(const char *address)
 {
     if (address == NULL)
     {
diff --git a/src/net_sdl.c b/src/net_sdl.c
index bfd89279..b889c9c9 100644
--- a/src/net_sdl.c
+++ b/src/net_sdl.c
@@ -325,7 +325,7 @@ void NET_SDL_AddrToString(net_addr_t *addr, char *buffer, int buffer_len)
     }
 }
 
-net_addr_t *NET_SDL_ResolveAddress(char *address)
+net_addr_t *NET_SDL_ResolveAddress(const char *address)
 {
     IPaddress ip;
     char *addr_hostname;