diff --git a/setup.py b/setup.py
index 83a6ae8..52106ef 100644
--- a/setup.py
+++ b/setup.py
@@ -29,7 +29,7 @@ def stamp_api_version():
 
 setup(
     name="science-synapse",
-    version="2.8.4",
+    version="2.8.5",
     description="Client library and CLI for the Synapse API",
     author="Science Team",
     author_email="team@science.xyz",
diff --git a/synapse-api b/synapse-api
index f9fc77f..551deca 160000
--- a/synapse-api
+++ b/synapse-api
@@ -1 +1 @@
-Subproject commit f9fc77f6c3a9b5ccfa6479b48f139e7d540e8843
+Subproject commit 551deca8d4f2cfd83be3264c371beb0b6fb70619
diff --git a/synapse/_api_version.py b/synapse/_api_version.py
index 445971d..3e7e1a1 100644
--- a/synapse/_api_version.py
+++ b/synapse/_api_version.py
@@ -1,2 +1,2 @@
 # Generated from synapse-api/VERSION by setup.py. Do not edit.
-SYNAPSE_API_VERSION = "2.6.0"
+SYNAPSE_API_VERSION = "2.6.1"
diff --git a/synapse/tests/client/test_spike_detector.py b/synapse/tests/client/test_spike_detector.py
index b64dcad..e7cc5b5 100644
--- a/synapse/tests/client/test_spike_detector.py
+++ b/synapse/tests/client/test_spike_detector.py
@@ -83,3 +83,13 @@ def test_to_proto_template_matcher():
     test_to_proto_template_matcher()
     print("All tests passed!")
 
+
+
+def test_negative_threshold_round_trips():
+    # threshold_uV is int32 (synapse-api 2.6.1): the sign is the crossing direction.
+    detector = SpikeDetector(samples_per_spike=32, config=ThresholderConfig(threshold_uV=-400))
+    proto = detector._to_proto().spike_detector
+    assert proto.thresholder.threshold_uV == -400
+
+    wire = SpikeDetectorConfig.FromString(proto.SerializeToString())
+    assert SpikeDetector._from_proto(wire).threshold_uV == -400