diff --git a/artiq/devices/pdq2/driver.py b/artiq/devices/pdq2/driver.py
index 481404d19..ea16a205b 100644
--- a/artiq/devices/pdq2/driver.py
+++ b/artiq/devices/pdq2/driver.py
@@ -198,13 +198,14 @@ class Pdq2:
             duration = line["duration"]
             trigger = line.get("trigger", False)
             for segment, data in zip(segments, line["channel_data"]):
+                silence = data.pop("silence", False)
                 if len(data) != 1:
                     raise ValueError("only one target per channel and line "
                                      "supported")
                 for target, target_data in data.items():
                     getattr(segment, target)(
                         shift=shift, duration=duration, trigger=trigger,
-                        **target_data)
+                        silence=silence, **target_data)
 
     def program(self, program, channels=None):
         if channels is None:
diff --git a/artiq/test/test_pdq2.py b/artiq/test/test_pdq2.py
index ef2c9bbf4..cfec3c7ab 100644
--- a/artiq/test/test_pdq2.py
+++ b/artiq/test/test_pdq2.py
@@ -31,7 +31,7 @@ class TestPdq2(unittest.TestCase):
         self.dev.program(_test_program)
         self.dev.cmd("START", True)
         self.dev.cmd("ARM", True)
-        #self.dev.cmd("TRIGGER", True)
+        # self.dev.cmd("TRIGGER", True)
         return self.dev.dev.getvalue()
 
     def test_synth(self):
@@ -103,10 +103,10 @@ _test_program = [
             "duration": 40,
             "channel_data": [
                 {"bias": {"amplitude": [.4, .04, -2e-3]}},
-                {"bias": {
-                    "amplitude": [.5],
+                {
+                    "bias": {"amplitude": [.5]},
                     "silence": True,
-                }},
+                },
                 {"dds": {
                     "amplitude": [.8, .08, -4e-3, 0],
                     "phase": [.25, .025, .02/40],
diff --git a/artiq/wavesynth/compute_samples.py b/artiq/wavesynth/compute_samples.py
index 1d48a81f5..9b80f8298 100644
--- a/artiq/wavesynth/compute_samples.py
+++ b/artiq/wavesynth/compute_samples.py
@@ -57,7 +57,7 @@ class DDS:
         return self.amplitude.next()*cos(2*pi*self.phase.next())
 
 
-class Wave:
+class Channel:
     def __init__(self):
         self.bias = Spline()
         self.dds = DDS()
@@ -80,7 +80,7 @@ class TriggerError(Exception):
 
 class Synthesizer:
     def __init__(self, nchannels, program):
-        self.channels = [Wave() for _ in range(nchannels)]
+        self.channels = [Channel() for _ in range(nchannels)]
         self.program = program
         # line_iter is None: "wait for segment selection" state
         # otherwise: iterator on the current position in the frame
@@ -104,6 +104,7 @@ class Synthesizer:
         while True:
             for channel, channel_data in zip(self.channels,
                                              line["channel_data"]):
+                channel.set_silence(channel_data.get("silence", False))
                 if "bias" in channel_data:
                     channel.bias.set_coefficients(
                         channel_data["bias"]["amplitude"])
@@ -115,7 +116,6 @@ class Synthesizer:
                             channel_data["dds"]["phase"])
                     if channel_data["dds"].get("clear", False):
                         channel.dds.phase.clear()
-                    channel.set_silence(channel_data.get("silence", False))
 
             if line.get("dac_divider", 1) != 1:
                 raise NotImplementedError