diff --git a/logging/rtc_event_log/events/rtc_event_generic_ack_received.cc b/logging/rtc_event_log/events/rtc_event_generic_ack_received.cc
index 2da2de6145..ba18d50ab6 100644
--- a/logging/rtc_event_log/events/rtc_event_generic_ack_received.cc
+++ b/logging/rtc_event_log/events/rtc_event_generic_ack_received.cc
@@ -23,6 +23,7 @@ RtcEventGenericAckReceived::CreateLogs(
     const std::vector<AckedPacket>& acked_packets) {
   std::vector<std::unique_ptr<RtcEventGenericAckReceived>> result;
   int64_t time_us = rtc::TimeMicros();
+  result.reserve(acked_packets.size());
   for (const AckedPacket& packet : acked_packets) {
     result.emplace_back(new RtcEventGenericAckReceived(
         time_us, packet_number, packet.packet_number,
diff --git a/test/network/network_emulation_manager.cc b/test/network/network_emulation_manager.cc
index 57c2703d2d..d4b4ffc337 100644
--- a/test/network/network_emulation_manager.cc
+++ b/test/network/network_emulation_manager.cc
@@ -244,6 +244,7 @@ EmulatedNetworkManagerInterface*
 NetworkEmulationManagerImpl::CreateEmulatedNetworkManagerInterface(
     const std::vector<EmulatedEndpoint*>& endpoints) {
   std::vector<EmulatedEndpointImpl*> endpoint_impls;
+  endpoint_impls.reserve(endpoints.size());
   for (EmulatedEndpoint* endpoint : endpoints) {
     endpoint_impls.push_back(static_cast<EmulatedEndpointImpl*>(endpoint));
   }