diff --git a/include/clap/ext/draft/state-context.h b/include/clap/ext/draft/state-context.h
index 4912a6e0..735ca2a7 100644
--- a/include/clap/ext/draft/state-context.h
+++ b/include/clap/ext/draft/state-context.h
@@ -27,7 +27,7 @@
 extern "C" {
 #endif
 
-static CLAP_CONSTEXPR const char CLAP_EXT_STATE_CONTEXT[] = "clap.state-context.draft/1";
+static CLAP_CONSTEXPR const char CLAP_EXT_STATE_CONTEXT[] = "clap.state-context.draft/2";
 
 enum clap_plugin_state_context_type {
    // suitable for duplicating a plugin instance
@@ -43,7 +43,7 @@ typedef struct clap_plugin_state_context {
    //
    // Note that the result may be loaded by both clap_plugin_state.load() and
    // clap_plugin_state_context.load().
-   // [main-thread]
+   // [state-thread]
    bool(CLAP_ABI *save)(const clap_plugin_t  *plugin,
                         const clap_ostream_t *stream,
                         uint32_t              context_type);
@@ -53,10 +53,23 @@ typedef struct clap_plugin_state_context {
    //
    // Note that the state may have been saved by clap_plugin_state.save() or
    // clap_plugin_state_context.save() with a different context_type.
-   // [main-thread]
+   // [state-thread]
    bool(CLAP_ABI *load)(const clap_plugin_t  *plugin,
                         const clap_istream_t *stream,
                         uint32_t              context_type);
+
+   // Indicates whether or not the plugin can support having a state-thread
+   // that is different than the main-thread.
+   //
+   // If this returns false, state-thread will always be the same as the
+   // main-thread.
+   //
+   // If this returns true, the state-thread may be a different thread than
+   // the main-thread.
+   //
+   // This must return the same result throughout the lifetime of the plugin.
+   // [thread-safe]
+   bool (CLAP_ABI *supports_async_state)(const clap_plugin_t *plugin);
 } clap_plugin_state_context_t;
 
 #ifdef __cplusplus
diff --git a/include/clap/ext/thread-check.h b/include/clap/ext/thread-check.h
index 6f8ef228..40644ba8 100644
--- a/include/clap/ext/thread-check.h
+++ b/include/clap/ext/thread-check.h
@@ -10,7 +10,7 @@ extern "C" {
 
 /// @page thread-check
 ///
-/// CLAP defines two symbolic threads:
+/// CLAP defines three symbolic threads:
 ///
 /// main-thread:
 ///    This is the thread in which most of the interaction between the plugin and host happens.
@@ -32,6 +32,12 @@ extern "C" {
 ///    including the main-thread as the audio-thread, as long as it can guarantee that only one OS
 ///    thread is the audio-thread at a time. The audio-thread can be seen as a concurrency guard for
 ///    all functions marked with [audio-thread].
+///
+/// state-thread:
+///    This thread is used for saving and loading plugin state. For plug-ins that don't support
+///    CLAP_EXT_STATE_CONTEXT, as well as plugins that return false from `supports_async_state`,
+///    this thread is always the same as the main-thread.
+///    For plugins
 
 // This interface is useful to do runtime checks and make
 // sure that the functions are called on the correct threads.