diff --git a/src/library_pthread.js b/src/library_pthread.js
index bff45471ffab..31349149a88c 100644
--- a/src/library_pthread.js
+++ b/src/library_pthread.js
@@ -551,14 +551,14 @@ var LibraryPThread = {
     worker.pthread_ptr = 0;
   },
 
-  __emscripten_thread_cleanup: (thread) => {
+  _emscripten_thread_cleanup: (thread) => {
     // Called when a thread needs to be cleaned up so it can be reused.
     // A thread is considered reusable when it either returns from its
     // entry point, calls pthread_exit, or acts upon a cancellation.
     // Detached threads are responsible for calling this themselves,
     // otherwise pthread_join is responsible for calling this.
 #if PTHREADS_DEBUG
-    dbg(`__emscripten_thread_cleanup: ${ptrToString(thread)}`)
+    dbg(`_emscripten_thread_cleanup: ${ptrToString(thread)}`)
 #endif
     if (!ENVIRONMENT_IS_PTHREAD) cleanupThread(thread);
     else postMessage({ 'cmd': 'cleanupThread', 'thread': thread });
@@ -702,7 +702,7 @@ var LibraryPThread = {
 #endif
     navigator['hardwareConcurrency'],
 
-  __emscripten_init_main_thread_js: (tb) => {
+  _emscripten_init_main_thread_js: (tb) => {
     // Pass the thread address to the native code where they stored in wasm
     // globals which act as a form of TLS. Global constructors trying
     // to access this value will read the wrong value, but that is UB anyway.
diff --git a/src/library_sigs.js b/src/library_sigs.js
index 1c09ee3ce962..c0c68dcd26df 100644
--- a/src/library_sigs.js
+++ b/src/library_sigs.js
@@ -225,8 +225,6 @@ sigs = {
   __cxa_rethrow_primary_exception__sig: 'vp',
   __cxa_throw__sig: 'vppp',
   __cxa_uncaught_exceptions__sig: 'i',
-  __emscripten_init_main_thread_js__sig: 'vp',
-  __emscripten_thread_cleanup__sig: 'vp',
   __handle_stack_overflow__sig: 'vp',
   __pthread_create_js__sig: 'ipppp',
   __pthread_kill_js__sig: 'ipi',
@@ -324,6 +322,7 @@ sigs = {
   _emscripten_fs_load_embedded_files__sig: 'vp',
   _emscripten_get_now_is_monotonic__sig: 'i',
   _emscripten_get_progname__sig: 'vpi',
+  _emscripten_init_main_thread_js__sig: 'vp',
   _emscripten_lookup_name__sig: 'ip',
   _emscripten_memcpy_js__sig: 'vppp',
   _emscripten_notify_mailbox_postmessage__sig: 'vppp',
@@ -333,6 +332,7 @@ sigs = {
   _emscripten_runtime_keepalive_clear__sig: 'v',
   _emscripten_set_offscreencanvas_size__sig: 'ipii',
   _emscripten_system__sig: 'ip',
+  _emscripten_thread_cleanup__sig: 'vp',
   _emscripten_thread_exit_joinable__sig: 'vp',
   _emscripten_thread_mailbox_await__sig: 'vp',
   _emscripten_thread_set_strongref__sig: 'vp',
diff --git a/src/library_wasm_worker.js b/src/library_wasm_worker.js
index 6a1073ae6fb5..f9fdcf6a922d 100644
--- a/src/library_wasm_worker.js
+++ b/src/library_wasm_worker.js
@@ -73,7 +73,7 @@ addToLibrary({
     '$_wasmWorkerDelayedMessageQueue',
     '$_wasmWorkerRunPostMessage',
     '$_wasmWorkerAppendToQueue',
-    'emscripten_wasm_worker_initialize',
+    '_emscripten_wasm_worker_initialize',
 #if PTHREADS
     '__set_thread_state',
 #endif
@@ -96,7 +96,7 @@ addToLibrary({
     ___set_stack_limits(m['sb'] + m['sz'], m['sb']);
 #endif
     // Run the C side Worker initialization for stack and TLS.
-    _emscripten_wasm_worker_initialize(m['sb'], m['sz']);
+    __emscripten_wasm_worker_initialize(m['sb'], m['sz']);
 #if PTHREADS
     // Record that this Wasm Worker supports synchronous blocking in emscripten_futex_wake().
     ___set_thread_state(/*thread_ptr=*/0, /*is_main_thread=*/0, /*is_runtime_thread=*/0, /*supports_wait=*/0);
diff --git a/system/lib/compiler-rt/stack_limits.S b/system/lib/compiler-rt/stack_limits.S
index 7bb9d895c46e..1c4c719fa18a 100644
--- a/system/lib/compiler-rt/stack_limits.S
+++ b/system/lib/compiler-rt/stack_limits.S
@@ -85,9 +85,9 @@ emscripten_stack_get_free:
 #ifdef __EMSCRIPTEN_WASM_WORKERS__
 # TODO: Relocate the following to its own file wasm_worker.S, but need to figure out how to reference
 # __stack_base and __stack_end globals from a separate file as externs in order for that to work.
-.globl emscripten_wasm_worker_initialize
-emscripten_wasm_worker_initialize:
-  .functype emscripten_wasm_worker_initialize (PTR /*stackLowestAddress*/, i32 /*stackSize*/) -> ()
+.globl _emscripten_wasm_worker_initialize
+_emscripten_wasm_worker_initialize:
+  .functype _emscripten_wasm_worker_initialize (PTR /*stackLowestAddress*/, i32 /*stackSize*/) -> ()
 
   // __stack_end = stackLowestAddress + (__builtin_wasm_tls_size() + 15) & -16;
   local.get 0
diff --git a/system/lib/libc/musl/src/thread/pthread_join.c b/system/lib/libc/musl/src/thread/pthread_join.c
index d209324a9ab8..a5d539b65175 100644
--- a/system/lib/libc/musl/src/thread/pthread_join.c
+++ b/system/lib/libc/musl/src/thread/pthread_join.c
@@ -45,7 +45,7 @@ static int __pthread_timedjoin_np(pthread_t t, void **res, const struct timespec
 	if (res) *res = t->result;
 #ifdef __EMSCRIPTEN__
 	// Thread was exited during this call, be sure to clean it up.
-	if (state == DT_EXITED) __emscripten_thread_cleanup(t);
+	if (state == DT_EXITED) _emscripten_thread_cleanup(t);
 #else // XXX Emscripten map_base unused
 	if (t->map_base) __munmap(t->map_base, t->map_size);
 #endif
diff --git a/system/lib/pthread/library_pthread.c b/system/lib/pthread/library_pthread.c
index 773e08668182..a90de5ff4011 100644
--- a/system/lib/pthread/library_pthread.c
+++ b/system/lib/pthread/library_pthread.c
@@ -137,8 +137,8 @@ weak_alias(dummy_tsd, __pthread_tsd_main);
 
 // See system/lib/README.md for static constructor ordering.
 __attribute__((constructor(48)))
-void __emscripten_init_main_thread(void) {
-  __emscripten_init_main_thread_js(&__main_pthread);
+void _emscripten_init_main_thread(void) {
+  _emscripten_init_main_thread_js(&__main_pthread);
 
   // The pthread struct has a field that points to itself - this is used as
   // a magic ID to detect whether the pthread_t structure is 'alive'.
diff --git a/system/lib/pthread/pthread_create.c b/system/lib/pthread/pthread_create.c
index d7050bbc7551..295fa1d52753 100644
--- a/system/lib/pthread/pthread_create.c
+++ b/system/lib/pthread/pthread_create.c
@@ -335,7 +335,7 @@ void _emscripten_thread_exit(void* result) {
   int state = a_cas(&self->detach_state, DT_JOINABLE, DT_EXITING);
 
   if (state == DT_DETACHED) {
-    __emscripten_thread_cleanup(self);
+    _emscripten_thread_cleanup(self);
   } else {
     // Mark the thread as no longer running, so it can be joined.
     // Once we publish this, any threads that are waiting to join with us can
diff --git a/system/lib/pthread/threading_internal.h b/system/lib/pthread/threading_internal.h
index 993c5665028e..121bfbeee57d 100644
--- a/system/lib/pthread/threading_internal.h
+++ b/system/lib/pthread/threading_internal.h
@@ -43,9 +43,9 @@ typedef struct thread_profiler_block {
 // the current time.
 void _emscripten_yield(double now);
 
-void __emscripten_init_main_thread_js(void* tb);
+void _emscripten_init_main_thread_js(void* tb);
 void _emscripten_thread_profiler_enable();
-void __emscripten_thread_cleanup(pthread_t thread);
+void _emscripten_thread_cleanup(pthread_t thread);
 
 hidden void* _emscripten_tls_init(void);
 hidden void _emscripten_tls_free(void);
diff --git a/test/other/metadce/test_metadce_minimal_pthreads.gzsize b/test/other/metadce/test_metadce_minimal_pthreads.gzsize
index 651ba07e2d02..cc1d64bcf857 100644
--- a/test/other/metadce/test_metadce_minimal_pthreads.gzsize
+++ b/test/other/metadce/test_metadce_minimal_pthreads.gzsize
@@ -1 +1 @@
-5254
+5253
diff --git a/tools/emscripten.py b/tools/emscripten.py
index 35df13bae9af..f73e2e1675b4 100644
--- a/tools/emscripten.py
+++ b/tools/emscripten.py
@@ -1042,11 +1042,11 @@ def create_pointer_conversion_wrappers(metadata):
     '_emscripten_thread_free_data': '_p',
     '_emscripten_dlsync_self_async': '_p',
     '_emscripten_proxy_dlsync_async': '_pp',
+    '_emscripten_wasm_worker_initialize': '_p_',
     '_wasmfs_rmdir': '_p',
     '_wasmfs_unlink': '_p',
     '_wasmfs_mkdir': '_p_',
     '_wasmfs_open': '_p__',
-    'emscripten_wasm_worker_initialize': '_p_',
     'asyncify_start_rewind': '_p',
     'asyncify_start_unwind': '_p',
     '__get_exception_message': '_ppp',