diff --git a/internal/ackhandler/sent_packet_handler.go b/internal/ackhandler/sent_packet_handler.go
index c6325a3ed..d731acd9e 100644
--- a/internal/ackhandler/sent_packet_handler.go
+++ b/internal/ackhandler/sent_packet_handler.go
@@ -159,6 +159,7 @@ func (h *sentPacketHandler) dropPackets(encLevel protocol.EncryptionLevel) {
 		panic(fmt.Sprintf("Cannot drop keys for encryption level %s", encLevel))
 	}
 	h.setLossDetectionTimer()
+	h.ptoCount = 0
 	h.ptoMode = SendNone
 }
 
diff --git a/internal/ackhandler/sent_packet_handler_test.go b/internal/ackhandler/sent_packet_handler_test.go
index ab2d64e08..3b700db0f 100644
--- a/internal/ackhandler/sent_packet_handler_test.go
+++ b/internal/ackhandler/sent_packet_handler_test.go
@@ -601,7 +601,7 @@ var _ = Describe("SentPacketHandler", func() {
 			Expect(handler.GetLossDetectionTimeout().Sub(sendTime)).To(Equal(4 * timeout))
 		})
 
-		It("resets the PTO mode when a packet number space is dropped", func() {
+		It("resets the PTO mode and PTO count when a packet number space is dropped", func() {
 			now := time.Now()
 			handler.SentPacket(ackElicitingPacket(&Packet{
 				PacketNumber:    1,
@@ -621,6 +621,7 @@ var _ = Describe("SentPacketHandler", func() {
 			// PTO timer based on the 1-RTT packet
 			Expect(handler.GetLossDetectionTimeout()).To(BeTemporally("~", now.Add(-time.Hour), time.Second))
 			Expect(handler.SendMode()).ToNot(Equal(SendPTOHandshake))
+			Expect(handler.ptoCount).To(BeZero())
 		})
 
 		It("allows two 1-RTT PTOs", func() {