diff --git a/sys/dev/hyperv/include/hyperv.h b/sys/dev/hyperv/include/hyperv.h
index 36512698fa7d..4257b371c717 100644
--- a/sys/dev/hyperv/include/hyperv.h
+++ b/sys/dev/hyperv/include/hyperv.h
@@ -24,6 +24,8 @@
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * $FreeBSD$
  */
 
 /**
@@ -669,6 +671,7 @@ typedef struct hv_vmbus_channel {
 	 * Allocated memory for ring buffer
 	 */
 	void*				ring_buffer_pages;
+	unsigned long			ring_buffer_size;
 	uint32_t			ring_buffer_page_count;
 	/*
 	 * send to parent
diff --git a/sys/dev/hyperv/vmbus/hv_channel.c b/sys/dev/hyperv/vmbus/hv_channel.c
index c467c2218469..103260a6adf7 100644
--- a/sys/dev/hyperv/vmbus/hv_channel.c
+++ b/sys/dev/hyperv/vmbus/hv_channel.c
@@ -104,17 +104,19 @@ hv_vmbus_channel_open(
 
 	/* Allocate the ring buffer */
 	out = contigmalloc((send_ring_buffer_size + recv_ring_buffer_size),
-		M_DEVBUF, M_ZERO, 0UL, BUS_SPACE_MAXADDR, PAGE_SIZE, 0);
+	    M_DEVBUF, M_ZERO, 0UL, BUS_SPACE_MAXADDR, PAGE_SIZE, 0);
 	KASSERT(out != NULL,
 	    ("Error VMBUS: contigmalloc failed to allocate Ring Buffer!"));
 	if (out == NULL)
-	    return (ENOMEM);
+		return (ENOMEM);
 
 	in = ((uint8_t *) out + send_ring_buffer_size);
 
 	new_channel->ring_buffer_pages = out;
-	new_channel->ring_buffer_page_count = (send_ring_buffer_size
-		+ recv_ring_buffer_size) >> PAGE_SHIFT;
+	new_channel->ring_buffer_page_count = (send_ring_buffer_size +
+	    recv_ring_buffer_size) >> PAGE_SHIFT;
+	new_channel->ring_buffer_size = send_ring_buffer_size +
+	    recv_ring_buffer_size;
 
 	hv_vmbus_ring_buffer_init(
 		&new_channel->outbound,
@@ -539,10 +541,8 @@ hv_vmbus_channel_close(hv_vmbus_channel *channel)
 	hv_ring_buffer_cleanup(&channel->outbound);
 	hv_ring_buffer_cleanup(&channel->inbound);
 
-	contigfree(
-		channel->ring_buffer_pages,
-		channel->ring_buffer_page_count,
-		M_DEVBUF);
+	contigfree(channel->ring_buffer_pages, channel->ring_buffer_size,
+	    M_DEVBUF);
 
 	free(info, M_DEVBUF);