diff --git a/labdata_plugin/analysisschema.py b/labdata_plugin/analysisschema.py
index ccf96e8..301c88b 100644
--- a/labdata_plugin/analysisschema.py
+++ b/labdata_plugin/analysisschema.py
@@ -224,7 +224,8 @@ class PsychophysicalKernel(dj.Computed):
     def key_source(self):
         subject_conditions = (
             dj.U("analysis_set_id", "subject_name", "trialset_description")
-            & BehaviorAnalysisSet.TrialSet()
+            .aggr(BehaviorAnalysisSet.TrialSet(), n_trialsets="count(*)")
+            .proj()
         )
         return subject_conditions * PsychophysicalKernelFitConfig()
 
diff --git a/src/behavior_analyses/kernel_timing.py b/src/behavior_analyses/kernel_timing.py
index 1bf1087..a6a0aa4 100644
--- a/src/behavior_analyses/kernel_timing.py
+++ b/src/behavior_analyses/kernel_timing.py
@@ -1,6 +1,5 @@
 from __future__ import annotations
 
-from importlib import import_module
 from typing import Any
 
 import numpy as np
@@ -339,18 +338,17 @@ def _fetch_chipmunk_trial_rows(dataset_key: dict[str, Any]) -> list[dict[str, An
 def _fetch_event_mapping_rows(
     session_key: dict[str, Any],
 ) -> list[dict[str, Any]]:
-    try:
-        import labdata
+    import datajoint as dj
+    import labdata
+    from labdata.schema import get_user_schema
 
-        labdata.plugins["gephys"].__file__
-        module = import_module("gephys.analysisschema")
+    try:
+        labdata.plugins["gephys"]
     except KeyError:
         return []
-    except ModuleNotFoundError as error:
-        if error.name in {"gephys", "gephys.analysisschema"}:
-            return []
-        raise
-    return list((module.EventMapping() & session_key).fetch(as_dict=True))
+    schema = get_user_schema()
+    table = dj.FreeTable(schema.connection, f"`{schema.database}`.`event_mapping`")
+    return list((table & session_key).fetch(as_dict=True))
 
 
 def _fetch_mapped_digital_event_rows(