diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9b9cadd4..24fb7b4c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -5,7 +5,7 @@ project(
   VERSION 4.3.0
   LANGUAGES CXX C)
 
-set(LIBCOAP_API_VERSION 2)
+set(LIBCOAP_API_VERSION 3)
 set(COAP_LIBRARY_NAME "coap-${LIBCOAP_API_VERSION}")
 
 option(
diff --git a/coap_config.h.lwip b/coap_config.h.lwip
index 8cce2042..2d9e3793 100644
--- a/coap_config.h.lwip
+++ b/coap_config.h.lwip
@@ -16,8 +16,8 @@
 #endif
 
 #define PACKAGE_NAME "libcoap"
-#define PACKAGE_VERSION "4.3.0rc1"
-#define PACKAGE_STRING "libcoap 4.3.0rc1"
+#define PACKAGE_VERSION "4.3.0rc2"
+#define PACKAGE_STRING "libcoap 4.3.0rc2"
 
 #define assert(x) LWIP_ASSERT("CoAP assert failed", x)
 
diff --git a/coap_config.h.riot b/coap_config.h.riot
index 08775645..0537d34c 100644
--- a/coap_config.h.riot
+++ b/coap_config.h.riot
@@ -100,10 +100,10 @@
 #define PACKAGE_NAME "libcoap"
 
 /* Define to the version of this package. */
-#define PACKAGE_VERSION "4.3.0rc1"
+#define PACKAGE_VERSION "4.3.0rc2"
 
 /* Define to the full name and version of this package. */
-#define PACKAGE_STRING "libcoap 4.3.0rc1"
+#define PACKAGE_STRING "libcoap 4.3.0rc2"
 
 /* Define to 1 if you have the ANSI C header files. */
 #define STDC_HEADERS 1
diff --git a/coap_config.h.windows b/coap_config.h.windows
index aec20b3c..f87271d5 100644
--- a/coap_config.h.windows
+++ b/coap_config.h.windows
@@ -78,7 +78,7 @@
 #define PACKAGE_NAME "libcoap"
 
 /* Define to the full name and version of this package. */
-#define PACKAGE_STRING "libcoap 4.3.0rc1"
+#define PACKAGE_STRING "libcoap 4.3.0rc2"
 
 /* Define to the one symbol short name of this package. */
 #define PACKAGE_TARNAME "libcoap"
@@ -87,7 +87,7 @@
 #define PACKAGE_URL "https://libcoap.net/"
 
 /* Define to the version of this package. */
-#define PACKAGE_VERSION "4.3.0rc1"
+#define PACKAGE_VERSION "4.3.0rc2"
 
 /* Define to 1 if you have the ANSI C header files. */
 #define STDC_HEADERS 1
diff --git a/configure.ac b/configure.ac
index cdaf6485..7f6ae181 100644
--- a/configure.ac
+++ b/configure.ac
@@ -13,7 +13,7 @@ m4_define([libcoap_micro_version], [0])
 
 # define an appending release state if needed, for example for pre-releases
 # like 'alpha' or 'rc1', for a full release keep the value empty!
-m4_define([libcoap_release_state], [rc1])
+m4_define([libcoap_release_state], [rc2])
 
 # concatenate the full libcoap version string
 m4_define([libcoap_version], [m4_format([%s.%s.%s%s], libcoap_major_version, libcoap_minor_version, libcoap_micro_version, libcoap_release_state)])
@@ -119,7 +119,7 @@ AC_SUBST(LT_LIBCOAP_AGE)
 AC_SUBST(LIBCOAP_SO_VERSION)
 
 # Defining the API Version
-LIBCOAP_API_VERSION=2
+LIBCOAP_API_VERSION=3
 AC_SUBST(LIBCOAP_API_VERSION)
 
 # Define a numeric version string
diff --git a/examples/coap-client.c b/examples/coap-client.c
index cdfbd0e5..f11826f0 100644
--- a/examples/coap-client.c
+++ b/examples/coap-client.c
@@ -41,7 +41,7 @@ static char* strndup(const char* s1, size_t n)
 #include <netdb.h>
 #endif
 
-#include <coap2/coap.h>
+#include <coap3/coap.h>
 
 #define MAX_USER 128 /* Maximum length of a user name (i.e., PSK
                       * identity) in bytes. */
diff --git a/examples/coap-rd.c b/examples/coap-rd.c
index a984625a..10f830d6 100644
--- a/examples/coap-rd.c
+++ b/examples/coap-rd.c
@@ -41,7 +41,7 @@
 #include <dirent.h>
 #endif
 
-#include <coap2/coap.h>
+#include <coap3/coap.h>
 
 #define COAP_RESOURCE_CHECK_TIME 2
 
diff --git a/examples/coap-server.c b/examples/coap-server.c
index 30c4d56c..904118c8 100644
--- a/examples/coap-server.c
+++ b/examples/coap-server.c
@@ -56,7 +56,7 @@ static char* strndup(const char* s1, size_t n)
 /* Need to refresh time once per sec */
 #define COAP_RESOURCE_CHECK_TIME 1
 
-#include <coap2/coap.h>
+#include <coap3/coap.h>
 
 #ifndef min
 #define min(a,b) ((a) < (b) ? (a) : (b))
diff --git a/examples/coap_list.c b/examples/coap_list.c
index 7486fbff..9f48079d 100644
--- a/examples/coap_list.c
+++ b/examples/coap_list.c
@@ -28,7 +28,7 @@
 #include <stdio.h>
 #include <string.h>
 
-#include <coap2/coap.h>
+#include <coap3/coap.h>
 
 int
 coap_insert(coap_list_t **head, coap_list_t *node) {
diff --git a/examples/coap_list.h b/examples/coap_list.h
index d8807009..3ce29fd1 100644
--- a/examples/coap_list.h
+++ b/examples/coap_list.h
@@ -28,7 +28,7 @@
 #ifndef COAP_LIST_H_
 #define COAP_LIST_H_
 
-#include <coap2/utlist.h>
+#include <coap3/utlist.h>
 
 typedef struct coap_list_t {
   struct coap_list_t *next;
diff --git a/examples/contiki/coap-observer.c b/examples/contiki/coap-observer.c
index 4f063263..68c74c7b 100644
--- a/examples/contiki/coap-observer.c
+++ b/examples/contiki/coap-observer.c
@@ -35,7 +35,7 @@
 
 #include <string.h>
 
-#include "coap2/coap.h"
+#include "coap3/coap.h"
 
 static coap_context_t *coap_context;
 
diff --git a/examples/contiki/server.c b/examples/contiki/server.c
index f726a058..4101658f 100644
--- a/examples/contiki/server.c
+++ b/examples/contiki/server.c
@@ -38,7 +38,7 @@
 
 #include <string.h>
 
-#include "coap2/coap.h"
+#include "coap3/coap.h"
 
 static coap_context_t *coap_context;
 
diff --git a/examples/etsi_iot_01.c b/examples/etsi_iot_01.c
index cdcce01a..040e5f3c 100644
--- a/examples/etsi_iot_01.c
+++ b/examples/etsi_iot_01.c
@@ -22,7 +22,7 @@
 #include <errno.h>
 #include <signal.h>
 
-#include <coap2/coap.h>
+#include <coap3/coap.h>
 
 #define COAP_RESOURCE_CHECK_TIME_SEC  1
 
diff --git a/examples/lwip/server-coap.c b/examples/lwip/server-coap.c
index ebde3f38..0faeb42c 100644
--- a/examples/lwip/server-coap.c
+++ b/examples/lwip/server-coap.c
@@ -1,5 +1,5 @@
 #include "coap_config.h"
-#include <coap2/coap.h>
+#include <coap3/coap.h>
 
 coap_context_t *main_coap_context;
 
diff --git a/examples/lwip/server-coap.h b/examples/lwip/server-coap.h
index 3ec726e1..ff0ec9a9 100644
--- a/examples/lwip/server-coap.h
+++ b/examples/lwip/server-coap.h
@@ -1,5 +1,5 @@
 #include "coap_config.h"
-#include <coap2/coap.h>
+#include <coap3/coap.h>
 
 void server_coap_init(void);
 /* call this when you think that resources could be dirty */
diff --git a/examples/tiny.c b/examples/tiny.c
index 057a2e44..93ffba65 100644
--- a/examples/tiny.c
+++ b/examples/tiny.c
@@ -19,7 +19,7 @@
 #include <netdb.h>
 #include <signal.h>
 
-#include <coap2/coap.h>
+#include <coap3/coap.h>
 
 #define Nn 8  /* duplicate definition of N if built on sky motes */
 #define ENCODE_HEADER_SIZE 4
diff --git a/include/coap2/address.h b/include/coap3/address.h
similarity index 100%
rename from include/coap2/address.h
rename to include/coap3/address.h
diff --git a/include/coap2/async.h b/include/coap3/async.h
similarity index 100%
rename from include/coap2/async.h
rename to include/coap3/async.h
diff --git a/include/coap2/bits.h b/include/coap3/bits.h
similarity index 100%
rename from include/coap2/bits.h
rename to include/coap3/bits.h
diff --git a/include/coap2/block.h b/include/coap3/block.h
similarity index 100%
rename from include/coap2/block.h
rename to include/coap3/block.h
diff --git a/include/coap2/coap.h.in b/include/coap3/coap.h.in
similarity index 100%
rename from include/coap2/coap.h.in
rename to include/coap3/coap.h.in
diff --git a/include/coap2/coap.h.windows b/include/coap3/coap.h.windows
similarity index 57%
rename from include/coap2/coap.h.windows
rename to include/coap3/coap.h.windows
index e44f0fcc..8e44390f 100644
--- a/include/coap2/coap.h.windows
+++ b/include/coap3/coap.h.windows
@@ -18,13 +18,13 @@
 #define LIBCOAP_PACKAGE_NAME "libcoap"
 
 /* Define the full name and version of libcoap. */
-#define LIBCOAP_PACKAGE_STRING "libcoap 4.3.0rc1"
+#define LIBCOAP_PACKAGE_STRING "libcoap 4.3.0rc2"
 
 /* Define the home page for libcoap. */
 #define LIBCOAP_PACKAGE_URL "https://libcoap.net/"
 
 /* Define the version of libcoap this file belongs to. */
-#define LIBCOAP_PACKAGE_VERSION "4.3.0rc1"
+#define LIBCOAP_PACKAGE_VERSION "4.3.0rc2"
 
 /* Define the numeric version identifier for libcoap */
 #define LIBCOAP_VERSION (4003000U)
@@ -33,29 +33,29 @@
 extern "C" {
 #endif
 
-#include "coap2/libcoap.h"
+#include "coap3/libcoap.h"
 
-#include "coap2/coap_forward_decls.h"
-#include "coap2/address.h"
-#include "coap2/async.h"
-#include "coap2/bits.h"
-#include "coap2/block.h"
-#include "coap2/coap_cache.h"
-#include "coap2/coap_debug.h"
-#include "coap2/coap_dtls.h"
-#include "coap2/coap_event.h"
-#include "coap2/coap_io.h"
-#include "coap2/coap_prng.h"
-#include "coap2/coap_time.h"
-#include "coap2/encode.h"
-#include "coap2/mem.h"
-#include "coap2/net.h"
-#include "coap2/option.h"
-#include "coap2/pdu.h"
-#include "coap2/resource.h"
-#include "coap2/str.h"
-#include "coap2/subscribe.h"
-#include "coap2/uri.h"
+#include "coap3/coap_forward_decls.h"
+#include "coap3/address.h"
+#include "coap3/async.h"
+#include "coap3/bits.h"
+#include "coap3/block.h"
+#include "coap3/coap_cache.h"
+#include "coap3/coap_debug.h"
+#include "coap3/coap_dtls.h"
+#include "coap3/coap_event.h"
+#include "coap3/coap_io.h"
+#include "coap3/coap_prng.h"
+#include "coap3/coap_time.h"
+#include "coap3/encode.h"
+#include "coap3/mem.h"
+#include "coap3/net.h"
+#include "coap3/option.h"
+#include "coap3/pdu.h"
+#include "coap3/resource.h"
+#include "coap3/str.h"
+#include "coap3/subscribe.h"
+#include "coap3/uri.h"
 
 #ifdef __cplusplus
 }
diff --git a/include/coap2/coap.h.windows.in b/include/coap3/coap.h.windows.in
similarity index 100%
rename from include/coap2/coap.h.windows.in
rename to include/coap3/coap.h.windows.in
diff --git a/include/coap2/coap_asn1_internal.h b/include/coap3/coap_asn1_internal.h
similarity index 100%
rename from include/coap2/coap_asn1_internal.h
rename to include/coap3/coap_asn1_internal.h
diff --git a/include/coap2/coap_async_internal.h b/include/coap3/coap_async_internal.h
similarity index 98%
rename from include/coap2/coap_async_internal.h
rename to include/coap3/coap_async_internal.h
index 49584d0b..15ffb103 100644
--- a/include/coap2/coap_async_internal.h
+++ b/include/coap3/coap_async_internal.h
@@ -15,7 +15,7 @@
 #ifndef COAP_ASYNC_INTERNAL_H_
 #define COAP_ASYNC_INTERNAL_H_
 
-#include "coap2/net.h"
+#include "coap3/net.h"
 
 #ifndef WITHOUT_ASYNC
 
diff --git a/include/coap2/coap_block_internal.h b/include/coap3/coap_block_internal.h
similarity index 100%
rename from include/coap2/coap_block_internal.h
rename to include/coap3/coap_block_internal.h
diff --git a/include/coap2/coap_cache.h b/include/coap3/coap_cache.h
similarity index 100%
rename from include/coap2/coap_cache.h
rename to include/coap3/coap_cache.h
diff --git a/include/coap2/coap_cache_internal.h b/include/coap3/coap_cache_internal.h
similarity index 100%
rename from include/coap2/coap_cache_internal.h
rename to include/coap3/coap_cache_internal.h
diff --git a/include/coap2/coap_debug.h b/include/coap3/coap_debug.h
similarity index 100%
rename from include/coap2/coap_debug.h
rename to include/coap3/coap_debug.h
diff --git a/include/coap2/coap_dtls.h b/include/coap3/coap_dtls.h
similarity index 100%
rename from include/coap2/coap_dtls.h
rename to include/coap3/coap_dtls.h
diff --git a/include/coap2/coap_dtls_internal.h b/include/coap3/coap_dtls_internal.h
similarity index 100%
rename from include/coap2/coap_dtls_internal.h
rename to include/coap3/coap_dtls_internal.h
diff --git a/include/coap2/coap_event.h b/include/coap3/coap_event.h
similarity index 100%
rename from include/coap2/coap_event.h
rename to include/coap3/coap_event.h
diff --git a/include/coap2/coap_forward_decls.h b/include/coap3/coap_forward_decls.h
similarity index 100%
rename from include/coap2/coap_forward_decls.h
rename to include/coap3/coap_forward_decls.h
diff --git a/include/coap2/coap_hashkey.h b/include/coap3/coap_hashkey.h
similarity index 100%
rename from include/coap2/coap_hashkey.h
rename to include/coap3/coap_hashkey.h
diff --git a/include/coap2/coap_internal.h b/include/coap3/coap_internal.h
similarity index 98%
rename from include/coap2/coap_internal.h
rename to include/coap3/coap_internal.h
index 0ae3dda0..36b55d31 100644
--- a/include/coap2/coap_internal.h
+++ b/include/coap3/coap_internal.h
@@ -33,7 +33,7 @@
 # include <assert.h>
 #endif
 
-#include "coap2/coap.h"
+#include "coap3/coap.h"
 
 /*
  * Include all the header files that are for internal use only.
diff --git a/include/coap2/coap_io.h b/include/coap3/coap_io.h
similarity index 100%
rename from include/coap2/coap_io.h
rename to include/coap3/coap_io.h
diff --git a/include/coap2/coap_io_internal.h b/include/coap3/coap_io_internal.h
similarity index 100%
rename from include/coap2/coap_io_internal.h
rename to include/coap3/coap_io_internal.h
diff --git a/include/coap2/coap_mutex.h b/include/coap3/coap_mutex.h
similarity index 100%
rename from include/coap2/coap_mutex.h
rename to include/coap3/coap_mutex.h
diff --git a/include/coap2/coap_net_internal.h b/include/coap3/coap_net_internal.h
similarity index 100%
rename from include/coap2/coap_net_internal.h
rename to include/coap3/coap_net_internal.h
diff --git a/include/coap2/coap_pdu_internal.h b/include/coap3/coap_pdu_internal.h
similarity index 100%
rename from include/coap2/coap_pdu_internal.h
rename to include/coap3/coap_pdu_internal.h
diff --git a/include/coap2/coap_prng.h b/include/coap3/coap_prng.h
similarity index 100%
rename from include/coap2/coap_prng.h
rename to include/coap3/coap_prng.h
diff --git a/include/coap2/coap_resource_internal.h b/include/coap3/coap_resource_internal.h
similarity index 100%
rename from include/coap2/coap_resource_internal.h
rename to include/coap3/coap_resource_internal.h
diff --git a/include/coap2/coap_riot.h b/include/coap3/coap_riot.h
similarity index 100%
rename from include/coap2/coap_riot.h
rename to include/coap3/coap_riot.h
diff --git a/include/coap2/coap_session.h b/include/coap3/coap_session.h
similarity index 100%
rename from include/coap2/coap_session.h
rename to include/coap3/coap_session.h
diff --git a/include/coap2/coap_session_internal.h b/include/coap3/coap_session_internal.h
similarity index 100%
rename from include/coap2/coap_session_internal.h
rename to include/coap3/coap_session_internal.h
diff --git a/include/coap2/coap_subscribe_internal.h b/include/coap3/coap_subscribe_internal.h
similarity index 100%
rename from include/coap2/coap_subscribe_internal.h
rename to include/coap3/coap_subscribe_internal.h
diff --git a/include/coap2/coap_tcp_internal.h b/include/coap3/coap_tcp_internal.h
similarity index 100%
rename from include/coap2/coap_tcp_internal.h
rename to include/coap3/coap_tcp_internal.h
diff --git a/include/coap2/coap_time.h b/include/coap3/coap_time.h
similarity index 100%
rename from include/coap2/coap_time.h
rename to include/coap3/coap_time.h
diff --git a/include/coap2/encode.h b/include/coap3/encode.h
similarity index 100%
rename from include/coap2/encode.h
rename to include/coap3/encode.h
diff --git a/include/coap2/libcoap.h b/include/coap3/libcoap.h
similarity index 100%
rename from include/coap2/libcoap.h
rename to include/coap3/libcoap.h
diff --git a/include/coap2/lwippools.h b/include/coap3/lwippools.h
similarity index 100%
rename from include/coap2/lwippools.h
rename to include/coap3/lwippools.h
diff --git a/include/coap2/mem.h b/include/coap3/mem.h
similarity index 100%
rename from include/coap2/mem.h
rename to include/coap3/mem.h
diff --git a/include/coap2/net.h b/include/coap3/net.h
similarity index 100%
rename from include/coap2/net.h
rename to include/coap3/net.h
diff --git a/include/coap2/option.h b/include/coap3/option.h
similarity index 100%
rename from include/coap2/option.h
rename to include/coap3/option.h
diff --git a/include/coap2/pdu.h b/include/coap3/pdu.h
similarity index 100%
rename from include/coap2/pdu.h
rename to include/coap3/pdu.h
diff --git a/include/coap2/resource.h b/include/coap3/resource.h
similarity index 100%
rename from include/coap2/resource.h
rename to include/coap3/resource.h
diff --git a/include/coap2/str.h b/include/coap3/str.h
similarity index 100%
rename from include/coap2/str.h
rename to include/coap3/str.h
diff --git a/include/coap2/subscribe.h b/include/coap3/subscribe.h
similarity index 100%
rename from include/coap2/subscribe.h
rename to include/coap3/subscribe.h
diff --git a/include/coap2/uri.h b/include/coap3/uri.h
similarity index 100%
rename from include/coap2/uri.h
rename to include/coap3/uri.h
diff --git a/include/coap2/uthash.h b/include/coap3/uthash.h
similarity index 100%
rename from include/coap2/uthash.h
rename to include/coap3/uthash.h
diff --git a/include/coap2/utlist.h b/include/coap3/utlist.h
similarity index 100%
rename from include/coap2/utlist.h
rename to include/coap3/utlist.h
diff --git a/libcoap-2.map b/libcoap-3.map
similarity index 100%
rename from libcoap-2.map
rename to libcoap-3.map
diff --git a/libcoap-2.pc.in b/libcoap-3.pc.in
similarity index 100%
rename from libcoap-2.pc.in
rename to libcoap-3.pc.in
diff --git a/libcoap-2.sym b/libcoap-3.sym
similarity index 100%
rename from libcoap-2.sym
rename to libcoap-3.sym
diff --git a/man/examples-code-check.c b/man/examples-code-check.c
index e49bf482..facbbfc5 100644
--- a/man/examples-code-check.c
+++ b/man/examples-code-check.c
@@ -100,7 +100,7 @@ static void check_synopsis(const char* file) {
     exit_code = 1;
     return;
   }
-  fprintf(fpcode, "#include <coap2/coap.h>\n");
+  fprintf(fpcode, "#include <coap3/coap.h>\n");
   fprintf(fpcode, "#ifdef __GNUC__\n");
   fprintf(fpcode, "#define U __attribute__ ((unused))\n");
   fprintf(fpcode, "#else /* not a GCC */\n");
@@ -412,7 +412,7 @@ int main(int argc, char* argv[])
         }
         if (fpcode) {
           if (strstr (buffer, "LIBCOAP_API_VERSION")) {
-            fprintf(fpcode, "#include <coap2/coap.h>\n");
+            fprintf(fpcode, "#include <coap3/coap.h>\n");
             fprintf(fpcode, "#ifdef __GNUC__\n");
             fprintf(fpcode, "#define U __attribute__ ((unused))\n");
             fprintf(fpcode, "#else /* not a GCC */\n");
diff --git a/src/address.c b/src/address.c
index d59b08ed..36c7d248 100644
--- a/src/address.c
+++ b/src/address.c
@@ -6,7 +6,7 @@
  * README for terms of use.
  */
 
-#include "coap2/coap_internal.h"
+#include "coap3/coap_internal.h"
 
 #if !defined(WITH_CONTIKI) && !defined(WITH_LWIP)
 #ifdef HAVE_ARPA_INET_H
diff --git a/src/async.c b/src/async.c
index 920dafe6..d6e41a6f 100644
--- a/src/async.c
+++ b/src/async.c
@@ -11,7 +11,7 @@
  * @brief state management for asynchronous messages
  */
 
-#include "coap2/coap_internal.h"
+#include "coap3/coap_internal.h"
 
 #ifndef WITHOUT_ASYNC
 
diff --git a/src/block.c b/src/block.c
index 3a88d713..f1c0aa63 100644
--- a/src/block.c
+++ b/src/block.c
@@ -6,7 +6,7 @@
  * README for terms of use.
  */
 
-#include "coap2/coap_internal.h"
+#include "coap3/coap_internal.h"
 
 #ifndef min
 #define min(a,b) ((a) < (b) ? (a) : (b))
diff --git a/src/coap_asn1.c b/src/coap_asn1.c
index 162266a0..9fccebd5 100644
--- a/src/coap_asn1.c
+++ b/src/coap_asn1.c
@@ -6,7 +6,7 @@
 * README for terms of use.
 */
 
-#include "coap2/coap_internal.h"
+#include "coap3/coap_internal.h"
 
 size_t
 asn1_len(const uint8_t **ptr)
diff --git a/src/coap_cache.c b/src/coap_cache.c
index 2072031e..94abdf1b 100644
--- a/src/coap_cache.c
+++ b/src/coap_cache.c
@@ -6,7 +6,7 @@
 * README for terms of use.
 */
 
-#include "coap2/coap_internal.h"
+#include "coap3/coap_internal.h"
 
 /* Determines if the given option_type denotes an option type that can
  * be used as CacheKey. Options that can be cache keys are not Unsafe
diff --git a/src/coap_debug.c b/src/coap_debug.c
index 59d3649c..54dabd4a 100644
--- a/src/coap_debug.c
+++ b/src/coap_debug.c
@@ -6,7 +6,7 @@
  * README for terms of use.
  */
 
-#include "coap2/coap_internal.h"
+#include "coap3/coap_internal.h"
 
 #if defined(HAVE_STRNLEN) && defined(__GNUC__) && !defined(_GNU_SOURCE)
 #define _GNU_SOURCE 1
diff --git a/src/coap_event.c b/src/coap_event.c
index aa390a0f..8e22f19c 100644
--- a/src/coap_event.c
+++ b/src/coap_event.c
@@ -7,7 +7,7 @@
  * of use.
  */
 
-#include "coap2/coap_internal.h"
+#include "coap3/coap_internal.h"
 
 /*
  * This replaces coap_set_event_handler() so that handler registration is
diff --git a/src/coap_gnutls.c b/src/coap_gnutls.c
index d8eb2772..757b0d2a 100644
--- a/src/coap_gnutls.c
+++ b/src/coap_gnutls.c
@@ -41,7 +41,7 @@
  * 3.6.6 or later is required to support Raw Public Key(RPK)
  */
 
-#include "coap2/coap_internal.h"
+#include "coap3/coap_internal.h"
 
 #ifdef HAVE_LIBGNUTLS
 
diff --git a/src/coap_hashkey.c b/src/coap_hashkey.c
index fc1965ae..b9f3906c 100644
--- a/src/coap_hashkey.c
+++ b/src/coap_hashkey.c
@@ -6,7 +6,7 @@
  * README for terms of use.
  */
 
-#include "coap2/coap_internal.h"
+#include "coap3/coap_internal.h"
 
 void
 coap_hash_impl(const unsigned char *s, size_t len, coap_key_t h) {
diff --git a/src/coap_io.c b/src/coap_io.c
index 803fef38..4b6acfcd 100644
--- a/src/coap_io.c
+++ b/src/coap_io.c
@@ -6,7 +6,7 @@
  * README for terms of use.
  */
 
-#include "coap2/coap_internal.h"
+#include "coap3/coap_internal.h"
 
 #ifdef HAVE_STDIO_H
 #  include <stdio.h>
diff --git a/src/coap_io_lwip.c b/src/coap_io_lwip.c
index 372a59eb..0bef7058 100644
--- a/src/coap_io_lwip.c
+++ b/src/coap_io_lwip.c
@@ -7,7 +7,7 @@
  * README for terms of use.
  */
 
-#include "coap2/coap_internal.h"
+#include "coap3/coap_internal.h"
 #include <lwip/udp.h>
 
 #if NO_SYS
diff --git a/src/coap_io_riot.c b/src/coap_io_riot.c
index f54f872c..22939dae 100644
--- a/src/coap_io_riot.c
+++ b/src/coap_io_riot.c
@@ -6,7 +6,7 @@
  * README for terms of use.
  */
 
-#include "coap2/coap_internal.h"
+#include "coap3/coap_internal.h"
 
 #ifdef HAVE_STDIO_H
 #  include <stdio.h>
diff --git a/src/coap_mbedtls.c b/src/coap_mbedtls.c
index 44b825a9..73d82d72 100644
--- a/src/coap_mbedtls.c
+++ b/src/coap_mbedtls.c
@@ -18,7 +18,7 @@
  * m_env      A coap_mbedtls_env_t * (held in c_session->tls)
  */
 
-#include "coap2/coap_internal.h"
+#include "coap3/coap_internal.h"
 
 #ifdef HAVE_MBEDTLS
 
diff --git a/src/coap_notls.c b/src/coap_notls.c
index 5592cede..1ce9e817 100644
--- a/src/coap_notls.c
+++ b/src/coap_notls.c
@@ -7,7 +7,7 @@
 * of use.
 */
 
-#include "coap2/coap_internal.h"
+#include "coap3/coap_internal.h"
 
 #if !defined(HAVE_LIBTINYDTLS) && !defined(HAVE_OPENSSL) && !defined(HAVE_LIBGNUTLS) && !defined(HAVE_MBEDTLS)
 
diff --git a/src/coap_openssl.c b/src/coap_openssl.c
index 1855f958..7e47325c 100644
--- a/src/coap_openssl.c
+++ b/src/coap_openssl.c
@@ -8,7 +8,7 @@
 * of use.
 */
 
-#include "coap2/coap_internal.h"
+#include "coap3/coap_internal.h"
 
 #ifdef HAVE_OPENSSL
 
diff --git a/src/coap_prng.c b/src/coap_prng.c
index 8be0ade1..39df4d41 100644
--- a/src/coap_prng.c
+++ b/src/coap_prng.c
@@ -7,7 +7,7 @@
  * for terms of use.
  */
 
-#include "coap2/coap_internal.h"
+#include "coap3/coap_internal.h"
 
 #ifdef HAVE_GETRANDOM
 #include <sys/random.h>
diff --git a/src/coap_session.c b/src/coap_session.c
index 53436ab3..818ce28a 100644
--- a/src/coap_session.c
+++ b/src/coap_session.c
@@ -6,7 +6,7 @@
 * README for terms of use.
 */
 
-#include "coap2/coap_internal.h"
+#include "coap3/coap_internal.h"
 
 #ifndef COAP_SESSION_C_
 #define COAP_SESSION_C_
diff --git a/src/coap_tcp.c b/src/coap_tcp.c
index db9faf45..9fa51aca 100644
--- a/src/coap_tcp.c
+++ b/src/coap_tcp.c
@@ -7,7 +7,7 @@
  * of use.
  */
 
-#include "coap2/coap_internal.h"
+#include "coap3/coap_internal.h"
 
 #include <errno.h>
 #include <sys/types.h>
diff --git a/src/coap_time.c b/src/coap_time.c
index 49d561ef..466f7694 100644
--- a/src/coap_time.c
+++ b/src/coap_time.c
@@ -6,7 +6,7 @@
  * README for terms of use.
  */
 
-#include "coap2/coap_internal.h"
+#include "coap3/coap_internal.h"
 
 #ifdef HAVE_TIME_H
 #include <time.h>
diff --git a/src/coap_tinydtls.c b/src/coap_tinydtls.c
index b308aec2..15c1e1e2 100644
--- a/src/coap_tinydtls.c
+++ b/src/coap_tinydtls.c
@@ -8,7 +8,7 @@
  * of use.
  */
 
-#include "coap2/coap_internal.h"
+#include "coap3/coap_internal.h"
 
 #ifdef HAVE_LIBTINYDTLS
 
diff --git a/src/encode.c b/src/encode.c
index 9f375c30..0df69fd2 100644
--- a/src/encode.c
+++ b/src/encode.c
@@ -6,7 +6,7 @@
  * README for terms of use.
  */
 
-#include "coap2/coap_internal.h"
+#include "coap3/coap_internal.h"
 
 /* Carsten suggested this when fls() is not available: */
 #ifndef HAVE_FLS
diff --git a/src/mem.c b/src/mem.c
index 55d81716..8572a294 100644
--- a/src/mem.c
+++ b/src/mem.c
@@ -7,7 +7,7 @@
  */
 
 
-#include "coap2/coap_internal.h"
+#include "coap3/coap_internal.h"
 
 #if defined(RIOT_VERSION) && defined(MODULE_MEMARRAY)
 #include <memarray.h>
diff --git a/src/net.c b/src/net.c
index f2c9aa8a..b28da8a9 100644
--- a/src/net.c
+++ b/src/net.c
@@ -6,7 +6,7 @@
  * README for terms of use.
  */
 
-#include "coap2/coap_internal.h"
+#include "coap3/coap_internal.h"
 
 #include <ctype.h>
 #include <stdio.h>
diff --git a/src/option.c b/src/option.c
index a87535cb..f4f649a6 100644
--- a/src/option.c
+++ b/src/option.c
@@ -8,7 +8,7 @@
  */
 
 
-#include "coap2/coap_internal.h"
+#include "coap3/coap_internal.h"
 
 #include <stdio.h>
 #include <string.h>
diff --git a/src/pdu.c b/src/pdu.c
index 19aaca32..b561ff74 100644
--- a/src/pdu.c
+++ b/src/pdu.c
@@ -6,7 +6,7 @@
  * README for terms of use.
  */
 
-#include "coap2/coap_internal.h"
+#include "coap3/coap_internal.h"
 
 #if defined(HAVE_LIMITS_H)
 #include <limits.h>
diff --git a/src/resource.c b/src/resource.c
index d97aca0a..b2273701 100644
--- a/src/resource.c
+++ b/src/resource.c
@@ -6,7 +6,7 @@
  * README for terms of use.
  */
 
-#include "coap2/coap_internal.h"
+#include "coap3/coap_internal.h"
 
 #include <stdio.h>
 #include <errno.h>
diff --git a/src/str.c b/src/str.c
index 36dbcb0a..ef7e2c3d 100644
--- a/src/str.c
+++ b/src/str.c
@@ -6,7 +6,7 @@
  * README for terms of use.
  */
 
-#include "coap2/coap_internal.h"
+#include "coap3/coap_internal.h"
 
 #include <stdio.h>
 
diff --git a/src/subscribe.c b/src/subscribe.c
index 0b554cc3..345fd82d 100644
--- a/src/subscribe.c
+++ b/src/subscribe.c
@@ -7,7 +7,7 @@
  * README for terms of use.
  */
 
-#include "coap2/coap_internal.h"
+#include "coap3/coap_internal.h"
 
 void
 coap_subscription_init(coap_subscription_t *s) {
diff --git a/src/uri.c b/src/uri.c
index 119822e0..5fae0821 100644
--- a/src/uri.c
+++ b/src/uri.c
@@ -6,7 +6,7 @@
  * README for terms of use.
  */
 
-#include "coap2/coap_internal.h"
+#include "coap3/coap_internal.h"
 
 #if defined(HAVE_LIMITS_H)
 #include <limits.h>
diff --git a/tests/oss-fuzz/pdu_parse_target.c b/tests/oss-fuzz/pdu_parse_target.c
index 57d8325f..d5f7d602 100644
--- a/tests/oss-fuzz/pdu_parse_target.c
+++ b/tests/oss-fuzz/pdu_parse_target.c
@@ -1,4 +1,4 @@
-#include <coap2/coap.h>
+#include <coap3/coap.h>
 
 int
 LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
diff --git a/tests/oss-fuzz/split_uri_target.c b/tests/oss-fuzz/split_uri_target.c
index 946618ff..7a8d0705 100644
--- a/tests/oss-fuzz/split_uri_target.c
+++ b/tests/oss-fuzz/split_uri_target.c
@@ -1,4 +1,4 @@
-#include <coap2/coap.h>
+#include <coap3/coap.h>
 
 int
 LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
diff --git a/win32/libcoap.props b/win32/libcoap.props
index b7f902b4..27c9a36c 100644
--- a/win32/libcoap.props
+++ b/win32/libcoap.props
@@ -17,7 +17,7 @@
     <CUnitIncludeDirDbg>$(CUnitRootDirDbg)include</CUnitIncludeDirDbg>
     <CUnitLibDir>$(CUnitRootDir)lib</CUnitLibDir>
     <CUnitLibDirDbg>$(CUnitRootDirDbg)lib</CUnitLibDirDbg>
-    <LibCoAPIncludeDir>include\coap2</LibCoAPIncludeDir>
+    <LibCoAPIncludeDir>include\coap3</LibCoAPIncludeDir>
   </PropertyGroup>
   <PropertyGroup />
   <ItemDefinitionGroup />