diff --git a/amiga/gui.c b/amiga/gui.c
index 3ba3d8957..249f80c89 100755
--- a/amiga/gui.c
+++ b/amiga/gui.c
@@ -3754,5 +3754,10 @@ uint32 ami_popup_hook(struct Hook *hook,Object *item,APTR reserved)
 
 static void *myrealloc(void *ptr, size_t len, void *pw)
 {
+	if (len == 0) {
+		free(ptr);
+		return NULL;
+	}
+
 	return realloc(ptr, len);
 }
diff --git a/beos/beos_gui.cpp b/beos/beos_gui.cpp
index cb41dfa07..471f4e9ea 100644
--- a/beos/beos_gui.cpp
+++ b/beos/beos_gui.cpp
@@ -1170,6 +1170,11 @@ bool cookies_update(const char *domain, const struct cookie_data *data)
 
 static void *myrealloc(void *ptr, size_t len, void *pw)
 {
+	if (len == 0) {
+		free(ptr);
+		return NULL;
+	}
+
 	return realloc(ptr, len);
 }
 
diff --git a/css/css.c b/css/css.c
index f051d52b9..7fb17519b 100644
--- a/css/css.c
+++ b/css/css.c
@@ -60,6 +60,11 @@ static nserror nscss_import(hlcache_handle *handle,
  */
 static void *myrealloc(void *ptr, size_t size, void *pw)
 {
+	if (size == 0) {
+		free(ptr);
+		return NULL;
+	}
+
 	return realloc(ptr, size);
 }
 
diff --git a/desktop/netsurf.c b/desktop/netsurf.c
index a69844f52..36832bb8c 100644
--- a/desktop/netsurf.c
+++ b/desktop/netsurf.c
@@ -51,6 +51,11 @@ bool verbose_log = false;
 
 static void *netsurf_lwc_alloc(void *ptr, size_t len, void *pw)
 {
+	if (len == 0) {
+		free(ptr);
+		return NULL;
+	}
+
 	return realloc(ptr, len);
 }
 
diff --git a/framebuffer/gui.c b/framebuffer/gui.c
index 287652d6e..10a2b329d 100644
--- a/framebuffer/gui.c
+++ b/framebuffer/gui.c
@@ -323,6 +323,11 @@ fb_browser_window_redraw(fbtk_widget_t *root, fbtk_widget_t *widget, void *pw)
 
 static void *myrealloc(void *ptr, size_t len, void *pw)
 {
+	if (len == 0) {
+		free(ptr);
+		return NULL;
+	}
+
 	return realloc(ptr, len);
 }
 
diff --git a/gtk/gtk_gui.c b/gtk/gtk_gui.c
index 3a749c67e..724c59c7d 100644
--- a/gtk/gtk_gui.c
+++ b/gtk/gtk_gui.c
@@ -537,6 +537,11 @@ void nsgtk_check_homedir(void)
  */
 void *nsgtk_hubbub_realloc(void *ptr, size_t len, void *pw)
 {
+	if (len == 0) {
+		free(ptr);
+		return NULL;
+	}
+
 	return realloc(ptr, len);
 }
 
diff --git a/render/box.c b/render/box.c
index 9bb7e59fe..e61dee8ff 100644
--- a/render/box.c
+++ b/render/box.c
@@ -50,6 +50,24 @@ struct box_duplicate_llist {
 };
 static struct box_duplicate_llist *box_duplicate_last = NULL;
 
+/**
+ * Allocator
+ *
+ * \param ptr   Pointer to reallocate, or NULL for new allocation
+ * \param size  Number of bytes requires
+ * \param pw    Allocation context
+ * \return Pointer to allocated block, or NULL on failure
+ */
+void *box_style_alloc(void *ptr, size_t len, void *pw)
+{
+	if (len == 0) {
+		free(ptr);
+		return NULL;
+	}
+
+	return realloc(ptr, len);
+}
+
 /**
  * Destructor for box nodes which own styles
  *
diff --git a/render/box.h b/render/box.h
index d1a1994f1..b6e344af1 100644
--- a/render/box.h
+++ b/render/box.h
@@ -294,7 +294,7 @@ extern const char *TARGET_BLANK;
 #define UNKNOWN_WIDTH INT_MAX
 #define UNKNOWN_MAX_WIDTH INT_MAX
 
-
+void *box_style_alloc(void *ptr, size_t len, void *pw);
 struct box * box_create(css_computed_style *style, bool style_owned,
 		char *href, const char *target, char *title,
 		char *id, void *context);
diff --git a/render/box_construct.c b/render/box_construct.c
index f7d92079b..153bdd75b 100644
--- a/render/box_construct.c
+++ b/render/box_construct.c
@@ -813,12 +813,6 @@ bool box_construct_text(xmlNode *n, struct content *content,
 	return true;
 }
 
-
-static void *ns_css_computed_style_alloc(void *ptr, size_t len, void *pw)
-{
-	return realloc(ptr, len);
-}
-
 /**
  * Get the style for an element.
  *
@@ -842,7 +836,7 @@ css_computed_style *box_get_style(struct content *c,
 				(uint8_t *) s, strlen(s),
 				c->data.html.encoding, content__get_url(c), 
 				c->data.html.quirks != BINDING_QUIRKS_MODE_NONE,
-				ns_css_computed_style_alloc, c);
+				box_style_alloc, NULL);
 
 		xmlFree(s);
 
@@ -853,7 +847,7 @@ css_computed_style *box_get_style(struct content *c,
 	/* Select partial style for element */
 	partial = nscss_get_style(c, n, CSS_PSEUDO_ELEMENT_NONE, 
 				  CSS_MEDIA_SCREEN, inline_style,
-				  ns_css_computed_style_alloc, c);
+				  box_style_alloc, NULL);
 
 	/* No longer need inline style */
 	if (inline_style != NULL)
diff --git a/render/box_normalise.c b/render/box_normalise.c
index 8af97535a..e082a9a6f 100644
--- a/render/box_normalise.c
+++ b/render/box_normalise.c
@@ -75,19 +75,6 @@ static bool calculate_table_row(struct columns *col_info,
 		unsigned int *start_column);
 static bool box_normalise_inline_container(struct box *cont, struct content *c);
 
-/**
- * Allocator
- *
- * \param ptr   Pointer to reallocate, or NULL for new allocation
- * \param size  Number of bytes requires
- * \param pw    Allocation context
- * \return Pointer to allocated block, or NULL on failure
- */
-static void *myrealloc(void *ptr, size_t len, void *pw)
-{
-	return talloc_realloc_size(pw, ptr, len);
-}
-
 /**
  * Ensure the box tree is correctly nested by adding and removing nodes.
  *
@@ -162,7 +149,7 @@ bool box_normalise_block(struct box *block, struct content *c)
 			assert(block->style != NULL);
 
 			style = nscss_get_blank_style(c, block->style,
-					myrealloc, c);
+					box_style_alloc, NULL);
 			if (style == NULL)
 				return false;
 
@@ -256,7 +243,7 @@ bool box_normalise_table(struct box *table, struct content * c)
 			assert(table->style != NULL);
 
 			style = nscss_get_blank_style(c, table->style,
-					myrealloc, c);
+					box_style_alloc, NULL);
 			if (style == NULL) {
 				free(col_info.spans);
 				return false;
@@ -335,7 +322,8 @@ bool box_normalise_table(struct box *table, struct content * c)
 
 		assert(table->style != NULL);
 
-		style = nscss_get_blank_style(c, table->style, myrealloc, c);
+		style = nscss_get_blank_style(c, table->style, 
+				box_style_alloc, NULL);
 		if (style == NULL) {
 			free(col_info.spans);
 			return false;
@@ -351,7 +339,7 @@ bool box_normalise_table(struct box *table, struct content * c)
 		row_group->type = BOX_TABLE_ROW_GROUP;
 
 		style = nscss_get_blank_style(c, row_group->style, 
-				myrealloc, c);
+				box_style_alloc, NULL);
 		if (style == NULL) {
 			box_free(row_group);
 			free(col_info.spans);
@@ -463,7 +451,7 @@ bool box_normalise_table_spans(struct box *table, struct span_info *spans,
 
 					style = nscss_get_blank_style(c, 
 							table_row->style,
-							myrealloc, c);
+							box_style_alloc, NULL);
 					if (style == NULL)
 						return false;
 
@@ -564,7 +552,7 @@ bool box_normalise_table_row_group(struct box *row_group,
 			assert(row_group->style != NULL);
 
 			style = nscss_get_blank_style(c, row_group->style,
-					myrealloc, c);
+					box_style_alloc, NULL);
 			if (style == NULL)
 				return false;
 
@@ -632,7 +620,7 @@ bool box_normalise_table_row_group(struct box *row_group,
 		assert(row_group->style != NULL);
 
 		style = nscss_get_blank_style(c, row_group->style, 
-				myrealloc, c);
+				box_style_alloc, NULL);
 		if (style == NULL) {
 			return false;
 		}
@@ -691,7 +679,7 @@ bool box_normalise_table_row(struct box *row,
 			assert(row->style != NULL);
 
 			style = nscss_get_blank_style(c, row->style, 
-					myrealloc, c);
+					box_style_alloc, NULL);
 			if (style == NULL)
 				return false;
 
diff --git a/render/html.c b/render/html.c
index 8d64f9515..caada3c96 100644
--- a/render/html.c
+++ b/render/html.c
@@ -106,6 +106,11 @@ static const char empty_document[] =
  */
 static void *myrealloc(void *ptr, size_t len, void *pw)
 {
+	if (len == 0) {
+		free(ptr);
+		return NULL;
+	}
+
 	return realloc(ptr, len);
 }
 
diff --git a/render/hubbub_binding.c b/render/hubbub_binding.c
index fc0a31944..bc509b4eb 100644
--- a/render/hubbub_binding.c
+++ b/render/hubbub_binding.c
@@ -128,6 +128,7 @@ static hubbub_tree_handler tree_handler = {
 
 static void *myrealloc(void *ptr, size_t len, void *pw)
 {
+	/* talloc_realloc_size(pw, ptr, 0) == talloc_free(ptr) */
 	return talloc_realloc_size(pw, ptr, len);
 }
 
diff --git a/riscos/gui.c b/riscos/gui.c
index 302587833..d3148529c 100644
--- a/riscos/gui.c
+++ b/riscos/gui.c
@@ -273,6 +273,11 @@ static void ro_gui_view_source_bounce(wimp_message *message);
 
 static void *myrealloc(void *ptr, size_t len, void *pw)
 {
+	if (len == 0) {
+		free(ptr);
+		return NULL;
+	}
+
 	return realloc(ptr, len);
 }
 
diff --git a/windows/gui.c b/windows/gui.c
index 047b2b9be..187430a3c 100644
--- a/windows/gui.c
+++ b/windows/gui.c
@@ -2284,6 +2284,11 @@ void gui_cert_verify(const char *url, const struct ssl_cert_info *certs,
 
 static void *myrealloc(void *ptr, size_t len, void *pw)
 {
+	if (len == 0) {
+		free(ptr);
+		return NULL;
+	}
+
 	return realloc(ptr, len);
 }