diff --git a/docs/c-api/net.h/struct_mg_mgr_init_opts.md b/docs/c-api/net.h/struct_mg_mgr_init_opts.md
index da3e49516593452736fb75b5194512cca397ba69..c0b6581662dc9224d2dfef941ab1d605eb6f8ca5 100644
--- a/docs/c-api/net.h/struct_mg_mgr_init_opts.md
+++ b/docs/c-api/net.h/struct_mg_mgr_init_opts.md
@@ -4,9 +4,9 @@ decl_name: "struct mg_mgr_init_opts"
 symbol_kind: "struct"
 signature: |
   struct mg_mgr_init_opts {
-    struct mg_iface_vtable *main_iface;
+    const struct mg_iface_vtable *main_iface;
     int num_ifaces;
-    struct mg_iface_vtable **ifaces;
+    const struct mg_iface_vtable **ifaces;
   };
 ---
 
diff --git a/mongoose.c b/mongoose.c
index 3f7534f8a6cb012526ec4a0619e74210323b78f7..91dc8b9f8702b7467795f0e70f4d20d3a491dbb5 100644
--- a/mongoose.c
+++ b/mongoose.c
@@ -2975,7 +2975,7 @@ extern "C" {
 #define MG_ENABLE_NET_IF_SOCKET MG_NET_IF == MG_NET_IF_SOCKET
 #endif
 
-extern struct mg_iface_vtable mg_socket_iface_vtable;
+extern const struct mg_iface_vtable mg_socket_iface_vtable;
 
 #ifdef __cplusplus
 }
@@ -3003,7 +3003,7 @@ struct mg_tun_client;
 extern "C" {
 #endif /* __cplusplus */
 
-extern struct mg_iface_vtable mg_tun_iface_vtable;
+extern const struct mg_iface_vtable mg_tun_iface_vtable;
 
 struct mg_connection *mg_tun_if_find_conn(struct mg_tun_client *client,
                                           uint32_t stream_id);
@@ -3023,18 +3023,18 @@ struct mg_connection *mg_tun_if_find_conn(struct mg_tun_client *client,
 /* Amalgamated: #include "mongoose/src/net_if_socket.h" */
 /* Amalgamated: #include "mongoose/src/net_if_tun.h" */
 
-extern struct mg_iface_vtable mg_default_iface_vtable;
+extern const struct mg_iface_vtable mg_default_iface_vtable;
 
 #if MG_ENABLE_TUN
-struct mg_iface_vtable *mg_ifaces[] = {&mg_default_iface_vtable,
-                                       &mg_tun_iface_vtable};
+const struct mg_iface_vtable *mg_ifaces[] = {&mg_default_iface_vtable,
+                                             &mg_tun_iface_vtable};
 #else
-struct mg_iface_vtable *mg_ifaces[] = {&mg_default_iface_vtable};
+const struct mg_iface_vtable *mg_ifaces[] = {&mg_default_iface_vtable};
 #endif
 
 int mg_num_ifaces = (int) (sizeof(mg_ifaces) / sizeof(mg_ifaces[0]));
 
-struct mg_iface *mg_if_create_iface(struct mg_iface_vtable *vtable,
+struct mg_iface *mg_if_create_iface(const struct mg_iface_vtable *vtable,
                                     struct mg_mgr *mgr) {
   struct mg_iface *iface = (struct mg_iface *) MG_CALLOC(1, sizeof(*iface));
   iface->mgr = mgr;
@@ -3044,7 +3044,7 @@ struct mg_iface *mg_if_create_iface(struct mg_iface_vtable *vtable,
 }
 
 struct mg_iface *mg_find_iface(struct mg_mgr *mgr,
-                               struct mg_iface_vtable *vtable,
+                               const struct mg_iface_vtable *vtable,
                                struct mg_iface *from) {
   int i = 0;
   if (from != NULL) {
@@ -3790,9 +3790,9 @@ void mg_socket_if_get_conn_addr(struct mg_connection *nc, int remote,
   }
 /* clang-format on */
 
-struct mg_iface_vtable mg_socket_iface_vtable = MG_SOCKET_IFACE_VTABLE;
+const struct mg_iface_vtable mg_socket_iface_vtable = MG_SOCKET_IFACE_VTABLE;
 #if MG_NET_IF == MG_NET_IF_SOCKET
-struct mg_iface_vtable mg_default_iface_vtable = MG_SOCKET_IFACE_VTABLE;
+const struct mg_iface_vtable mg_default_iface_vtable = MG_SOCKET_IFACE_VTABLE;
 #endif
 
 #endif /* MG_ENABLE_NET_IF_SOCKET */
@@ -3966,7 +3966,7 @@ struct mg_connection *mg_tun_if_find_conn(struct mg_tun_client *client,
   }
 /* clang-format on */
 
-struct mg_iface_vtable mg_tun_iface_vtable = MG_TUN_IFACE_VTABLE;
+const struct mg_iface_vtable mg_tun_iface_vtable = MG_TUN_IFACE_VTABLE;
 
 #endif /* MG_ENABLE_TUN */
 #ifdef MG_MODULE_LINES
@@ -13012,7 +13012,7 @@ extern "C" {
 #define MG_ENABLE_NET_IF_SIMPLELINK MG_NET_IF == MG_NET_IF_SIMPLELINK
 #endif
 
-extern struct mg_iface_vtable mg_simplelink_iface_vtable;
+extern const struct mg_iface_vtable mg_simplelink_iface_vtable;
 
 #ifdef __cplusplus
 }
@@ -13484,9 +13484,9 @@ void sl_restart_cb(struct mg_mgr *mgr) {
   }
 /* clang-format on */
 
-struct mg_iface_vtable mg_simplelink_iface_vtable = MG_SL_IFACE_VTABLE;
+const struct mg_iface_vtable mg_simplelink_iface_vtable = MG_SL_IFACE_VTABLE;
 #if MG_NET_IF == MG_NET_IF_SIMPLELINK
-struct mg_iface_vtable mg_default_iface_vtable = MG_SL_IFACE_VTABLE;
+const struct mg_iface_vtable mg_default_iface_vtable = MG_SL_IFACE_VTABLE;
 #endif
 
 #endif /* MG_ENABLE_NET_IF_SIMPLELINK */
@@ -13706,7 +13706,7 @@ int sl_set_ssl_opts(struct mg_connection *nc) {
 
 #include <stdint.h>
 
-extern struct mg_iface_vtable mg_lwip_iface_vtable;
+extern const struct mg_iface_vtable mg_lwip_iface_vtable;
 
 struct mg_lwip_conn_state {
   struct mg_connection *nc;
@@ -14355,9 +14355,9 @@ void mg_lwip_if_sock_set(struct mg_connection *nc, sock_t sock) {
   }
 /* clang-format on */
 
-struct mg_iface_vtable mg_lwip_iface_vtable = MG_LWIP_IFACE_VTABLE;
+const struct mg_iface_vtable mg_lwip_iface_vtable = MG_LWIP_IFACE_VTABLE;
 #if MG_NET_IF == MG_NET_IF_LWIP_LOW_LEVEL
-struct mg_iface_vtable mg_default_iface_vtable = MG_LWIP_IFACE_VTABLE;
+const struct mg_iface_vtable mg_default_iface_vtable = MG_LWIP_IFACE_VTABLE;
 #endif
 
 #endif /* MG_ENABLE_NET_IF_LWIP_LOW_LEVEL */
@@ -14902,7 +14902,7 @@ extern "C" {
 #define MG_ENABLE_NET_IF_PIC32 MG_NET_IF == MG_NET_IF_PIC32
 #endif
 
-extern struct mg_iface_vtable mg_pic32_iface_vtable;
+extern const struct mg_iface_vtable mg_pic32_iface_vtable;
 
 #ifdef __cplusplus
 }
@@ -15201,9 +15201,9 @@ void mg_pic32_if_connect_udp(struct mg_connection *nc) {
   }
 /* clang-format on */
 
-struct mg_iface_vtable mg_pic32_iface_vtable = MG_PIC32_IFACE_VTABLE;
+const struct mg_iface_vtable mg_pic32_iface_vtable = MG_PIC32_IFACE_VTABLE;
 #if MG_NET_IF == MG_NET_IF_PIC32
-struct mg_iface_vtable mg_default_iface_vtable = MG_PIC32_IFACE_VTABLE;
+const struct mg_iface_vtable mg_default_iface_vtable = MG_PIC32_IFACE_VTABLE;
 #endif
 
 #endif /* MG_ENABLE_NET_IF_PIC32 */
diff --git a/mongoose.h b/mongoose.h
index 45fab927b6283d84d74b9a8f04c80b60981367a1..0812f9a5fdbcfd78faba8a1d5db383e93d033e93 100644
--- a/mongoose.h
+++ b/mongoose.h
@@ -3002,7 +3002,7 @@ struct mg_iface_vtable;
 struct mg_iface {
   struct mg_mgr *mgr;
   void *data; /* Implementation-specific data */
-  struct mg_iface_vtable *vtable;
+  const struct mg_iface_vtable *vtable;
 };
 
 struct mg_iface_vtable {
@@ -3041,11 +3041,11 @@ struct mg_iface_vtable {
                         union socket_address *sa);
 };
 
-extern struct mg_iface_vtable *mg_ifaces[];
+extern const struct mg_iface_vtable *mg_ifaces[];
 extern int mg_num_ifaces;
 
 /* Creates a new interface instance. */
-struct mg_iface *mg_if_create_iface(struct mg_iface_vtable *vtable,
+struct mg_iface *mg_if_create_iface(const struct mg_iface_vtable *vtable,
                                     struct mg_mgr *mgr);
 
 /*
@@ -3053,7 +3053,7 @@ struct mg_iface *mg_if_create_iface(struct mg_iface_vtable *vtable,
  * interface `from`, exclusive. Returns NULL if none is found.
  */
 struct mg_iface *mg_find_iface(struct mg_mgr *mgr,
-                               struct mg_iface_vtable *vtable,
+                               const struct mg_iface_vtable *vtable,
                                struct mg_iface *from);
 /*
  * Deliver a new TCP connection. Returns NULL in case on error (unable to
@@ -3348,9 +3348,9 @@ void mg_mgr_init(struct mg_mgr *mgr, void *user_data);
  * `num_ifaces` pointers it contains will be reclaimed by `mg_mgr_free`.
  */
 struct mg_mgr_init_opts {
-  struct mg_iface_vtable *main_iface;
+  const struct mg_iface_vtable *main_iface;
   int num_ifaces;
-  struct mg_iface_vtable **ifaces;
+  const struct mg_iface_vtable **ifaces;
 };
 
 /*