diff --git a/src/toffy/watcher_callbacks.py b/src/toffy/watcher_callbacks.py
index 4e12f76b..cd3648bf 100644
--- a/src/toffy/watcher_callbacks.py
+++ b/src/toffy/watcher_callbacks.py
@@ -301,7 +301,7 @@ def generate_pulse_heights(self, pulse_out_dir: str, panel: pd.DataFrame = None,
         if not os.path.exists(pulse_out_dir):
             os.makedirs(pulse_out_dir)
 
-        pulse_height_file = os.path.join(pulse_out_dir, f"{self.point_name}-pulse_heights.csv")
+        pulse_height_file = os.path.join(pulse_out_dir, f"{self.point_name}_pulse_heights.csv")
         if os.path.exists(pulse_height_file) and not self.overwrite:
             warnings.warn(f"Pulse heights per mass already extracted for FOV {self.point_name}")
             return
diff --git a/tests/fov_watcher_test.py b/tests/fov_watcher_test.py
index fd551e3e..e64d5e85 100644
--- a/tests/fov_watcher_test.py
+++ b/tests/fov_watcher_test.py
@@ -303,7 +303,7 @@ def test_watcher(
                 df_ph = pd.DataFrame(np.random.rand(10, 3), columns=["mass", "fov", "pulse_height"])
                 df_ph["fov"] = "fov-2-scan-1"
                 df_ph.to_csv(
-                    os.path.join(pulse_out_dir, "fov-2-scan-1-pulse_heights.csv"), index=False
+                    os.path.join(pulse_out_dir, "fov-2-scan-1_pulse_heights.csv"), index=False
                 )
 
             # `_slow_copy_sample_tissue_data` mimics the instrument computer uploading data to the