diff --git a/arbor/backends/event_stream_base.hpp b/arbor/backends/event_stream_base.hpp
index 0b3fb940a..0e62d6ddf 100644
--- a/arbor/backends/event_stream_base.hpp
+++ b/arbor/backends/event_stream_base.hpp
@@ -119,7 +119,7 @@ struct spike_event_stream_base: event_stream_base<deliverable_event> {
                 arb_assert(div + evt.target < handles.size());
                 const auto& handle = handles[div + evt.target];
                 auto& stream = streams[handle.mech_id];
-                stream.spikes_.push_back(spike_data(step, handle.mech_index, evt.time, evt.weight));
+                stream.spikes_.emplace_back({step, handle.mech_index, evt.time, evt.weight});
                 stream.ev_spans_[step + 1]++;
             }
             ++cell;
@@ -139,7 +139,7 @@ struct spike_event_stream_base: event_stream_base<deliverable_event> {
                 std::sort(stream.spikes_.begin(), stream.spikes_.end());
                 // copy temporary deliverable_events into stream's ev_data_
                 stream.ev_data_.reserve(stream.spikes_.size());
-                for (const auto& spike: stream.spikes_) stream.ev_data_.emplace_back(spike.mech_index, spike.weight);
+                for (const auto& spike: stream.spikes_) stream.ev_data_.emplace_back({spike.mech_index, spike.weight});
                 // delegate to derived class init: static cast necessary to access protected init()
                 static_cast<spike_event_stream_base&>(stream).init();
             // });