diff --git a/system/lib/libc/musl/src/thread/__timedwait.c b/system/lib/libc/musl/src/thread/__timedwait.c
index 5d37774c8555a..9539b0b90c1a3 100644
--- a/system/lib/libc/musl/src/thread/__timedwait.c
+++ b/system/lib/libc/musl/src/thread/__timedwait.c
@@ -59,18 +59,14 @@ int __timedwait_cp(volatile int *addr, int val,
 
 #ifdef __EMSCRIPTEN__
 	double msecsToSleep = top ? (top->tv_sec * 1000 + top->tv_nsec / 1000000.0) : INFINITY;
-	int is_runtime_thread = emscripten_is_main_runtime_thread();
 
 	// cp suffix in the function name means "cancellation point", so this wait can be cancelled
 	// by the users unless current threads cancelability is set to PTHREAD_CANCEL_DISABLE
 	// which may be either done by the user of __timedwait() function.
 	pthread_t self = pthread_self();
-	if (is_runtime_thread ||
-	    self->canceldisable != PTHREAD_CANCEL_DISABLE ||
-	    self->cancelasync) {
-		// Main runtime thread may need to run proxied calls, so sleep in very small slices to be responsive.
-		double max_ms_slice_to_sleep = is_runtime_thread ? 1 : 100;
 
+	if (self->canceldisable != PTHREAD_CANCEL_DISABLE) {
+		double max_ms_slice_to_sleep = 100;
 		double sleepUntilTime = emscripten_get_now() + msecsToSleep;
 		do {
 			if (self->cancel) {
@@ -79,7 +75,7 @@ int __timedwait_cp(volatile int *addr, int val,
 				// __pthread_testcancel(), which won't return at all.
 				__pthread_testcancel();
 				// If __pthread_testcancel does return here it means that canceldisable
-				// must be set to PTHREAD_CANCEL_MASKED.  This appear to mean "return
+				// must be set to PTHREAD_CANCEL_MASKED.  This appears to mean "return
 				// ECANCELLED to the caller".  See pthread_cond_timedwait.c for the only
 				// use of this that I could find.
 				return ECANCELED;
diff --git a/system/lib/pthread/emscripten_futex_wait.c b/system/lib/pthread/emscripten_futex_wait.c
index 963622492d5dc..7a37e9bc33fcc 100644
--- a/system/lib/pthread/emscripten_futex_wait.c
+++ b/system/lib/pthread/emscripten_futex_wait.c
@@ -49,6 +49,7 @@ static int futex_wait_main_browser_thread(volatile void* addr,
   while (1) {
 #ifdef __EMSCRIPTEN_PTHREADS__
     if (cancelable && pthread_self()->cancel) {
+      __pthread_testcancel();
       return -ETIMEDOUT;
     }
 #endif
@@ -213,7 +214,7 @@ int emscripten_futex_wait(volatile void *addr, uint32_t val, double max_wait_ms)
 #endif
 #ifdef __EMSCRIPTEN_PTHREADS__
     if (cancelable && ret == ATOMICS_WAIT_TIMED_OUT && self->cancel) {
-      // Break out of the loop early if we were cancelled
+      __pthread_testcancel();
       break;
     }
     // If remainder_ns is negative it means we want wait forever, and we don't
diff --git a/test/codesize/test_codesize_minimal_pthreads.json b/test/codesize/test_codesize_minimal_pthreads.json
index ed8abbc889665..286657e60f5b4 100644
--- a/test/codesize/test_codesize_minimal_pthreads.json
+++ b/test/codesize/test_codesize_minimal_pthreads.json
@@ -1,10 +1,10 @@
 {
   "a.out.js": 7363,
   "a.out.js.gz": 3604,
-  "a.out.nodebug.wasm": 19256,
-  "a.out.nodebug.wasm.gz": 8935,
-  "total": 26619,
-  "total_gz": 12539,
+  "a.out.nodebug.wasm": 19239,
+  "a.out.nodebug.wasm.gz": 8916,
+  "total": 26602,
+  "total_gz": 12520,
   "sent": [
     "a (memory)",
     "b (emscripten_get_now)",
diff --git a/test/codesize/test_codesize_minimal_pthreads_memgrowth.json b/test/codesize/test_codesize_minimal_pthreads_memgrowth.json
index 50a3f3afc8a34..2136612149cb0 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": 7765,
   "a.out.js.gz": 3810,
-  "a.out.nodebug.wasm": 19257,
-  "a.out.nodebug.wasm.gz": 8936,
-  "total": 27022,
-  "total_gz": 12746,
+  "a.out.nodebug.wasm": 19240,
+  "a.out.nodebug.wasm.gz": 8917,
+  "total": 27005,
+  "total_gz": 12727,
   "sent": [
     "a (memory)",
     "b (emscripten_get_now)",