diff --git a/moo/lib/exec.c b/moo/lib/exec.c
index bbdc8cf..d01f5bc 100644
--- a/moo/lib/exec.c
+++ b/moo/lib/exec.c
@@ -1341,6 +1341,34 @@ static int delete_from_sem_io (moo_t* moo, moo_oop_semaphore_t sem, int force)
 	return 0;
 }
 
+void moo_purgesemiosbyhandle (moo_t* moo, moo_ooi_t io_handle)
+{
+	moo_ooi_t index;
+	moo_oop_semaphore_t sem;
+
+	if (io_handle < moo->sem_io_map_capa)
+	{
+		index = moo->sem_io_map[io_handle];
+		if (index >= 0)
+		{
+			MOO_ASSERT(moo, moo->sem_io_tuple[index].handle == io_handle);
+			sem = moo->sem_io_tuple[index].sem[MOO_SEMAPHORE_IO_TYPE_INPUT];
+			if (sem) delete_from_sem_io (moo, sem, 0);
+		}
+	}
+
+	if (io_handle < moo->sem_io_map_capa)
+	{
+		index = moo->sem_io_map[io_handle];
+		if (index >= 0)
+		{
+			MOO_ASSERT(moo, moo->sem_io_tuple[index].handle == io_handle);
+			sem = moo->sem_io_tuple[index].sem[MOO_SEMAPHORE_IO_TYPE_OUTPUT];
+			if (sem) delete_from_sem_io (moo, sem, 0);
+		}
+	}
+}
+
 static void _signal_io_semaphore (moo_t* moo, moo_oop_semaphore_t sem)
 {
 	moo_oop_process_t proc;
diff --git a/moo/lib/main.c b/moo/lib/main.c
index 0f8d2ec..23e377c 100644
--- a/moo/lib/main.c
+++ b/moo/lib/main.c
@@ -599,7 +599,7 @@ static void* dl_open (moo_t* moo, const moo_ooch_t* name, int flags)
 
 static void dl_close (moo_t* moo, void* handle)
 {
-#if defined(USE_LTDL) | defined(USE_DLFCN)
+#if defined(USE_LTDL) || defined(USE_DLFCN)
 	MOO_DEBUG1 (moo, "Closed DL handle %p\n", handle);
 	sys_dl_close (handle);
 
diff --git a/moo/lib/moo.h b/moo/lib/moo.h
index 3473f7d..10e4caa 100644
--- a/moo/lib/moo.h
+++ b/moo/lib/moo.h
@@ -2152,6 +2152,15 @@ MOO_EXPORT const moo_ooch_t* moo_errnum_to_errstr (
 	moo_errnum_t errnum
 );
 
+/**
+ * The moo_purgesemiosbyhandle() function deletes IO semaphores associated
+ * with the given IO handle. It can be called usefaully when you close 
+ * a IO handle with dangling semaphores associated.
+ */
+MOO_EXPORT void moo_purgesemiosbyhandle (
+	moo_t*    moo,
+	moo_ooi_t io_handle
+);
 
 #if defined(MOO_INCLUDE_COMPILER)
 
diff --git a/moo/mod/sck.c b/moo/mod/sck.c
index 9df0284..e36c7e6 100644
--- a/moo/mod/sck.c
+++ b/moo/mod/sck.c
@@ -132,6 +132,7 @@ static moo_pfrc_t pf_close_socket (moo_t* moo, moo_ooi_t nargs)
 	fd = MOO_OOP_TO_SMOOI(sck->handle);
 	if (fd >= 0)
 	{
+		moo_purgesemiobyhandle (moo, MOO_OOP_TO_SMOOI(sck->handle));
 		if (close(MOO_OOP_TO_SMOOI(sck->handle)) == -1)
 		{
 			moo_seterrwithsyserr (moo, errno);