diff --git a/include/coap3/coap_async.h b/include/coap3/coap_async.h
index fcb9eb85bb..f26ec7b012 100644
--- a/include/coap3/coap_async.h
+++ b/include/coap3/coap_async.h
@@ -86,7 +86,7 @@ COAP_API void coap_async_trigger(coap_async_t *async);
  * @param session  The session to use.
  * @param async The object to delete.
  */
-void coap_free_async(coap_session_t *session, coap_async_t *async);
+COAP_API void coap_free_async(coap_session_t *session, coap_async_t *async);
 
 /**
  * Retrieves the object identified by @p token from the list of asynchronous
diff --git a/include/coap3/coap_net_internal.h b/include/coap3/coap_net_internal.h
index 0c0b28547f..2a4f270f92 100644
--- a/include/coap3/coap_net_internal.h
+++ b/include/coap3/coap_net_internal.h
@@ -216,11 +216,13 @@ int coap_insert_node(coap_queue_t **queue, coap_queue_t *node);
 /**
  * Destroys specified @p node.
  *
+ * Note: Not a part of the Public API.
+ *
  * @param node Node entry to remove.
  *
  * @return @c 1 node deleted from queue, @c 0 failure.
  */
-int coap_delete_node(coap_queue_t *node);
+COAP_API int coap_delete_node(coap_queue_t *node);
 
 /**
  * Destroys specified @p node.
diff --git a/include/coap3/coap_oscore.h b/include/coap3/coap_oscore.h
index 7b35603dae..51ddba0a81 100644
--- a/include/coap3/coap_oscore.h
+++ b/include/coap3/coap_oscore.h
@@ -54,11 +54,11 @@ int coap_oscore_is_supported(void);
  * @return A new CoAP session or NULL if failed. Call coap_session_release()
  *         to free.
  */
-coap_session_t *coap_new_client_session_oscore(coap_context_t *ctx,
-                                               const coap_address_t *local_if,
-                                               const coap_address_t *server,
-                                               coap_proto_t proto,
-                                               coap_oscore_conf_t *oscore_conf);
+COAP_API coap_session_t *coap_new_client_session_oscore(coap_context_t *ctx,
+                                                        const coap_address_t *local_if,
+                                                        const coap_address_t *server,
+                                                        coap_proto_t proto,
+                                                        coap_oscore_conf_t *oscore_conf);
 
 /**
  * Creates a new client session to the designated server with PSK credentials
diff --git a/include/coap3/coap_session.h b/include/coap3/coap_session.h
index 2573c000cc..63f85f461b 100644
--- a/include/coap3/coap_session.h
+++ b/include/coap3/coap_session.h
@@ -253,12 +253,11 @@ COAP_API size_t coap_session_max_pdu_size(const coap_session_t *session);
  *
  * @return A new CoAP session or NULL if failed. Call coap_session_release to free.
  */
-COAP_API coap_session_t *coap_new_client_session(
-    coap_context_t *ctx,
-    const coap_address_t *local_if,
-    const coap_address_t *server,
-    coap_proto_t proto
-);
+COAP_API coap_session_t *coap_new_client_session(coap_context_t *ctx,
+                                                 const coap_address_t *local_if,
+                                                 const coap_address_t *server,
+                                                 coap_proto_t proto
+                                                );
 
 /**
  * Creates a new client session to the designated server with PSK credentials
@@ -303,12 +302,12 @@ COAP_API coap_session_t *coap_new_client_session_psk(coap_context_t *ctx,
  * @return A new CoAP session or NULL if failed. Call coap_session_release()
  *         to free.
  */
-coap_session_t *coap_new_client_session_psk2(coap_context_t *ctx,
-                                             const coap_address_t *local_if,
-                                             const coap_address_t *server,
-                                             coap_proto_t proto,
-                                             coap_dtls_cpsk_t *setup_data
-                                            );
+COAP_API coap_session_t *coap_new_client_session_psk2(coap_context_t *ctx,
+                                                      const coap_address_t *local_if,
+                                                      const coap_address_t *server,
+                                                      coap_proto_t proto,
+                                                      coap_dtls_cpsk_t *setup_data
+                                                     );
 
 /**
  * Get the server session's current Identity Hint (PSK).
diff --git a/src/coap_async.c b/src/coap_async.c
index 60115ab11f..3d7183da3d 100644
--- a/src/coap_async.c
+++ b/src/coap_async.c
@@ -193,7 +193,7 @@ coap_free_async_sub(coap_context_t *context, coap_async_t *s) {
   }
 }
 
-void
+COAP_API void
 coap_free_async(coap_session_t *session, coap_async_t *async) {
   coap_lock_lock(session->context, return);
   coap_free_async_lkd(session, async);
diff --git a/src/coap_net.c b/src/coap_net.c
index f5c958a910..91140c14b2 100644
--- a/src/coap_net.c
+++ b/src/coap_net.c
@@ -200,7 +200,7 @@ coap_insert_node(coap_queue_t **queue, coap_queue_t *node) {
   return 1;
 }
 
-int
+COAP_API int
 coap_delete_node(coap_queue_t *node) {
   int ret;
 #if COAP_THREAD_SAFE
@@ -4257,7 +4257,7 @@ coap_event_name(coap_event_t event) {
 }
 #endif /* COAP_MAX_LOGGING_LEVEL >= _COAP_LOG_DEBUG */
 
-int
+COAP_API int
 coap_handle_event(coap_context_t *context, coap_event_t event,
                   coap_session_t *session) {
   int ret;
@@ -4754,7 +4754,7 @@ coap_mcast_set_hops(coap_session_t *session, size_t hops) {
 #endif /* COAP_CLIENT_SUPPORT */
 
 #else /* defined WITH_CONTIKI || defined WITH_LWIP */
-int
+COAP_API int
 coap_join_mcast_group_intf(coap_context_t *ctx COAP_UNUSED,
                            const char *group_name COAP_UNUSED,
                            const char *ifname COAP_UNUSED) {