diff --git a/src/modules/echo-cancel/module-echo-cancel.c b/src/modules/echo-cancel/module-echo-cancel.c
index f7c72763a..5c639ae0b 100644
--- a/src/modules/echo-cancel/module-echo-cancel.c
+++ b/src/modules/echo-cancel/module-echo-cancel.c
@@ -2104,6 +2104,11 @@ int main(int argc, char* argv[]) {
     source_ss.channels = DEFAULT_CHANNELS;
     pa_channel_map_init_auto(&source_map, source_ss.channels, PA_CHANNEL_MAP_DEFAULT);
 
+    sink_ss.format = PA_SAMPLE_S16LE;
+    sink_ss.rate = DEFAULT_RATE;
+    sink_ss.channels = DEFAULT_CHANNELS;
+    pa_channel_map_init_auto(&sink_map, sink_ss.channels, PA_CHANNEL_MAP_DEFAULT);
+
     if (init_common(ma, &u, &source_ss, &source_map) < 0)
         goto fail;