diff --git a/quic/core/quic_unacked_packet_map.h b/quic/core/quic_unacked_packet_map.h
index 2e5a64e..137d3f8 100644
--- a/quic/core/quic_unacked_packet_map.h
+++ b/quic/core/quic_unacked_packet_map.h
@@ -320,13 +320,13 @@
   }
 
   std::string DebugString() const {
-    return quiche::QuicheStringPrintf(
-        "{size: %zu, least_unacked: %s, largest_sent_packet: %s, "
-        "largest_acked: %s, bytes_in_flight: %zu, packets_in_flight: %zu}",
-        unacked_packets_size(), least_unacked_.ToString().c_str(),
-        largest_sent_packet_.ToString().c_str(),
-        largest_acked_.ToString().c_str(), bytes_in_flight_,
-        packets_in_flight_);
+    return quiche::QuicheStrCat(
+        "{size: ", unacked_packets_size(),
+        ", least_unacked: ", least_unacked_.ToString(),
+        ", largest_sent_packet: ", largest_sent_packet_.ToString(),
+        ", largest_acked: ", largest_acked_.ToString(),
+        ", bytes_in_flight: ", bytes_in_flight_,
+        ", packets_in_flight: ", packets_in_flight_, "}");
   }
 
  private:
diff --git a/quic/core/quic_unacked_packet_map_test.cc b/quic/core/quic_unacked_packet_map_test.cc
index 8a3d00b..4b598be 100644
--- a/quic/core/quic_unacked_packet_map_test.cc
+++ b/quic/core/quic_unacked_packet_map_test.cc
@@ -669,7 +669,7 @@
   ASSERT_EQ(QuicUnackedPacketMapPeer::GetCapacity(unacked_packets), 16u);
 }
 
-TEST_P(QuicUnackedPacketMapTest, QUIC_TEST_DISABLED_IN_CHROME(DebugString)) {
+TEST_P(QuicUnackedPacketMapTest, DebugString) {
   EXPECT_EQ(unacked_packets_.DebugString(),
             "{size: 0, least_unacked: 1, largest_sent_packet: uninitialized, "
             "largest_acked: uninitialized, bytes_in_flight: 0, "