diff --git a/system/lib/libc/musl/src/thread/pthread_mutex_unlock.c b/system/lib/libc/musl/src/thread/pthread_mutex_unlock.c
index af13bcfa12012..9e10a22c30348 100644
--- a/system/lib/libc/musl/src/thread/pthread_mutex_unlock.c
+++ b/system/lib/libc/musl/src/thread/pthread_mutex_unlock.c
@@ -14,7 +14,7 @@ int __pthread_mutex_unlock(pthread_mutex_t *m)
 		self = __pthread_self();
 		old = m->_m_lock;
 		int own = old & 0x3fffffff;
-		if (own != self->tid)
+		if (own != CURRENT_THREAD_ID)
 			return EPERM;
 		if ((type&3) == PTHREAD_MUTEX_RECURSIVE && m->_m_count)
 			return m->_m_count--, 0;
diff --git a/test/codesize/test_codesize_minimal_pthreads.json b/test/codesize/test_codesize_minimal_pthreads.json
index 7fc88d7cafe97..d17b05e9ccd93 100644
--- a/test/codesize/test_codesize_minimal_pthreads.json
+++ b/test/codesize/test_codesize_minimal_pthreads.json
@@ -1,10 +1,10 @@
 {
   "a.out.js": 7367,
   "a.out.js.gz": 3605,
-  "a.out.nodebug.wasm": 19095,
-  "a.out.nodebug.wasm.gz": 8830,
-  "total": 26462,
-  "total_gz": 12435,
+  "a.out.nodebug.wasm": 19097,
+  "a.out.nodebug.wasm.gz": 8828,
+  "total": 26464,
+  "total_gz": 12433,
   "sent": [
     "a (memory)",
     "b (exit)",
diff --git a/test/codesize/test_codesize_minimal_pthreads_memgrowth.json b/test/codesize/test_codesize_minimal_pthreads_memgrowth.json
index 6c771a690712c..da438fcd16f34 100644
--- a/test/codesize/test_codesize_minimal_pthreads_memgrowth.json
+++ b/test/codesize/test_codesize_minimal_pthreads_memgrowth.json
@@ -1,10 +1,10 @@
 {
   "a.out.js": 7769,
   "a.out.js.gz": 3811,
-  "a.out.nodebug.wasm": 19096,
-  "a.out.nodebug.wasm.gz": 8831,
-  "total": 26865,
-  "total_gz": 12642,
+  "a.out.nodebug.wasm": 19098,
+  "a.out.nodebug.wasm.gz": 8829,
+  "total": 26867,
+  "total_gz": 12640,
   "sent": [
     "a (memory)",
     "b (exit)",