diff --git a/docker/Dockerfile.base b/docker/Dockerfile.base
index 58643e6f..222dcf99 100644
--- a/docker/Dockerfile.base
+++ b/docker/Dockerfile.base
@@ -14,7 +14,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   libvulkan-dev \
   python3-numpy
 WORKDIR /root
-RUN git clone https://github.com/iqtlabs/gr-iqtlabs -b 1.0.101
+RUN git clone https://github.com/iqtlabs/gr-iqtlabs -b 1.0.102
 COPY --from=iqtlabs/gamutrf-vkfft:latest /root /root/gr-iqtlabs
 WORKDIR /root/gr-iqtlabs/build
 COPY --from=iqtlabs/gamutrf-sigmf:latest /usr/local /usr/local
diff --git a/gamutrf/grsource.py b/gamutrf/grsource.py
index 835c56df..744425b6 100644
--- a/gamutrf/grsource.py
+++ b/gamutrf/grsource.py
@@ -69,6 +69,7 @@ def __init__(
             int(self.n_samples / self.tagged_interval) * self.tagged_interval
         )
         logging.info("opened %s with %u samples", input_file, self.n_samples)
+        self.work_guard = None
 
     def complete(self):
         return self.i >= self.n_samples
@@ -115,8 +116,18 @@ def add_tags(self):
 
     def general_work(self, input_items, output_items):
         if self.complete():
+            # gnuradio will drop all undelivered messages to blocks when our source
+            # returns done. cause gnuradio to repeatedly call us when we're done, to
+            # give other blocks an opportunity to process undelivered messages.
+            if self.work_guard is None:
+                self.work_guard = time.time()
+                logging.info("file ended, waiting for other blocks to finish")
+                return 0
+            if time.time() - self.work_guard < 3:
+                return 0
             logging.info("complete")
             return -1
+
         n = min(self.nfft, len(output_items[0]))
         samples = self.samples[self.i : self.i + n]
         c = len(samples)