diff --git a/lib/core-net/lws-dsh.c b/lib/core-net/lws-dsh.c
index 3391b1c85..c641f79d0 100644
--- a/lib/core-net/lws-dsh.c
+++ b/lib/core-net/lws-dsh.c
@@ -1,7 +1,7 @@
 /*
  * libwebsockets - small server side websockets and web server implementation
  *
- * Copyright (C) 2010 - 2019 Andy Green <andy@warmcat.com>
+ * Copyright (C) 2010 - 2021 Andy Green <andy@warmcat.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to
@@ -60,6 +60,7 @@ lws_dsh_create(lws_dll2_owner_t *owner, size_t buf_len, int count_kinds)
 	assert(buf_len);
 	assert(count_kinds > 1);
 	assert(buf_len > sizeof(lws_dsh_t) + oha_len);
+	buf_len += 64;
 
 	dsh = lws_malloc(sizeof(lws_dsh_t) + buf_len + oha_len, __func__);
 	if (!dsh)
@@ -76,8 +77,10 @@ lws_dsh_create(lws_dll2_owner_t *owner, size_t buf_len, int count_kinds)
 	/* clear down the obj heads array */
 
 	memset(dsh->oha, 0, oha_len);
-	for (n = 0; n < count_kinds; n++)
+	for (n = 0; n < count_kinds; n++) {
 		dsh->oha[n].kind = n;
+		dsh->oha[n].total_size = 0;
+	}
 
 	/* initially the whole buffer is on the free kind (0) list */
 
@@ -296,6 +299,7 @@ _lws_dsh_alloc_tail(lws_dsh_t *dsh, int kind, const void *src1, size_t size1,
 		 */
 		lws_dll2_remove(&s.best->list);
 		s.best->dsh = s.dsh;
+		s.best->kind = kind;
 		s.best->size = size1 + size2;
 		memcpy(&s.best[1], src1, size1);
 		if (src2)
@@ -310,12 +314,15 @@ _lws_dsh_alloc_tail(lws_dsh_t *dsh, int kind, const void *src1, size_t size1,
 			if (replace->next)
 				replace->next->prev = &s.best->list;
 		} else
-			if (dsh)
+			if (dsh) {
+				assert(!(((unsigned long)(intptr_t)(s.best)) & (sizeof(int *) - 1)));
 				lws_dll2_add_tail(&s.best->list, &dsh->oha[kind].owner);
+			}
 
 		assert(s.dsh->locally_free >= s.best->asize);
 		s.dsh->locally_free -= s.best->asize;
 		s.dsh->locally_in_use += s.best->asize;
+		dsh->oha[kind].total_size += s.best->asize;
 		assert(s.dsh->locally_in_use <= s.dsh->buffer_size);
 	} else {
 		lws_dsh_obj_t *obj;
@@ -334,10 +341,11 @@ _lws_dsh_alloc_tail(lws_dsh_t *dsh, int kind, const void *src1, size_t size1,
 
 		/* latter part becomes new object */
 
-		obj = (lws_dsh_obj_t *)(((uint8_t *)s.best) + s.best->asize);
+		obj = (lws_dsh_obj_t *)(((uint8_t *)s.best) + lws_dsh_align(s.best->asize));
 
 		lws_dll2_clear(&obj->list);
 		obj->dsh = s.dsh;
+		obj->kind = kind;
 		obj->size = size1 + size2;
 		obj->asize = asize;
 
@@ -354,12 +362,15 @@ _lws_dsh_alloc_tail(lws_dsh_t *dsh, int kind, const void *src1, size_t size1,
 			if (replace->next)
 				replace->next->prev = &s.best->list;
 		} else
-			if (dsh)
+			if (dsh) {
+				assert(!(((unsigned long)(intptr_t)(obj)) & (sizeof(int *) - 1)));
 				lws_dll2_add_tail(&obj->list, &dsh->oha[kind].owner);
+			}
 
 		assert(s.dsh->locally_free >= asize);
 		s.dsh->locally_free -= asize;
 		s.dsh->locally_in_use += asize;
+		dsh->oha[kind].total_size += asize;
 		assert(s.dsh->locally_in_use <= s.dsh->buffer_size);
 	}
 
@@ -402,6 +413,7 @@ lws_dsh_free(void **pobj)
 	assert(dsh->locally_in_use >= _o->asize);
 	dsh->locally_free += _o->asize;
 	dsh->locally_in_use -= _o->asize;
+	dsh->oha[_o->kind].total_size -= _o->asize; /* account for usage by kind */
 	assert(dsh->locally_in_use <= dsh->buffer_size);
 
 	/*
@@ -469,7 +481,7 @@ lws_dsh_get_head(lws_dsh_t *dsh, int kind, void **obj, size_t *size)
 	*size = _obj->size;
 
 	/* anything coming out of here must be aligned */
-	assert(!(((unsigned long)(*obj)) & (sizeof(int *) - 1)));
+	assert(!(((unsigned long)(intptr_t)(*obj)) & (sizeof(int *) - 1)));
 
 	return 0;	/* we returned the head */
 }
diff --git a/lib/core-net/private-lib-core-net.h b/lib/core-net/private-lib-core-net.h
index 9cbb0c2bb..eac480352 100644
--- a/lib/core-net/private-lib-core-net.h
+++ b/lib/core-net/private-lib-core-net.h
@@ -270,6 +270,7 @@ struct lws_timed_vh_protocol {
 
 typedef struct lws_dsh_obj_head {
 	lws_dll2_owner_t		owner;
+	size_t				total_size; /* for this kind in dsh */
 	int				kind;
 } lws_dsh_obj_head_t;
 
@@ -278,6 +279,7 @@ typedef struct lws_dsh_obj {
 	struct lws_dsh	  		*dsh;	/* invalid when on free list */
 	size_t				size;	/* invalid when on free list */
 	size_t				asize;
+	int				kind; /* so we can account at free */
 } lws_dsh_obj_t;
 
 typedef struct lws_dsh {