diff --git a/coap_config.h.lwip b/coap_config.h.lwip
index 13d0fb2a..077c6ac5 100644
--- a/coap_config.h.lwip
+++ b/coap_config.h.lwip
@@ -27,8 +27,8 @@
 #endif
 
 #define PACKAGE_NAME "libcoap"
-#define PACKAGE_VERSION "4.3.0"
-#define PACKAGE_STRING "libcoap 4.3.0"
+#define PACKAGE_VERSION "4.3.1rc1"
+#define PACKAGE_STRING "libcoap 4.3.1rc1"
 
 #define assert(x) LWIP_ASSERT("CoAP assert failed", x)
 
diff --git a/coap_config.h.riot b/coap_config.h.riot
index 1ca0fc5e..17244494 100644
--- a/coap_config.h.riot
+++ b/coap_config.h.riot
@@ -111,10 +111,10 @@
 #define PACKAGE_NAME "libcoap"
 
 /* Define to the version of this package. */
-#define PACKAGE_VERSION "4.3.0"
+#define PACKAGE_VERSION "4.3.1rc1"
 
 /* Define to the full name and version of this package. */
-#define PACKAGE_STRING "libcoap 4.3.0"
+#define PACKAGE_STRING "libcoap 4.3.1rc1"
 
 /* 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 6a81518a..9836855e 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 4.3.0"
+#define PACKAGE_STRING "libcoap 4.3.1rc1"
 
 /* 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 "4.3.0"
+#define PACKAGE_VERSION "4.3.1rc1"
 
 /* Define to 1 if you have the ANSI C header files. */
 #define STDC_HEADERS 1
diff --git a/configure.ac b/configure.ac
index a63b4539..da085f3a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -15,11 +15,11 @@
 # defined later.
 m4_define([libcoap_major_version], [4])
 m4_define([libcoap_minor_version], [3])
-m4_define([libcoap_micro_version], [0])
+m4_define([libcoap_micro_version], [1])
 
 # 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], [])
+m4_define([libcoap_release_state], [rc1])
 
 # 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)])
diff --git a/include/coap3/coap.h.windows b/include/coap3/coap.h.windows
index c5148422..2c083179 100644
--- a/include/coap3/coap.h.windows
+++ b/include/coap3/coap.h.windows
@@ -20,16 +20,16 @@
 #define LIBCOAP_PACKAGE_NAME "libcoap"
 
 /* Define the full name and version of libcoap. */
-#define LIBCOAP_PACKAGE_STRING "libcoap 4.3.0"
+#define LIBCOAP_PACKAGE_STRING "libcoap 4.3.1rc1"
 
 /* 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 "4.3.0"
+#define LIBCOAP_PACKAGE_VERSION "4.3.1rc1"
 
 /* Define the numeric version identifier for libcoap */
-#define LIBCOAP_VERSION (4003000U)
+#define LIBCOAP_VERSION (4003001U)
 
 #ifdef __cplusplus
 extern "C" {