diff --git a/src/pulsecore/sink-input.c b/src/pulsecore/sink-input.c
index 6dfbdbb04..6ef1e93d5 100644
--- a/src/pulsecore/sink-input.c
+++ b/src/pulsecore/sink-input.c
@@ -145,7 +145,7 @@ pa_sink_input* pa_sink_input_new(
         if (pa_channel_map_compatible(&data->sink->channel_map, &data->sample_spec))
             data->channel_map = data->sink->channel_map;
         else
-            pa_return_null_if_fail(pa_channel_map_init_auto(&data->channel_map, data->sample_spec.channels, PA_CHANNEL_MAP_DEFAULT));
+            pa_channel_map_init_extend(&data->channel_map, data->sample_spec.channels, PA_CHANNEL_MAP_DEFAULT);
     }
 
     pa_return_null_if_fail(pa_channel_map_valid(&data->channel_map));
diff --git a/src/pulsecore/source-output.c b/src/pulsecore/source-output.c
index 6af78241a..7adc7572e 100644
--- a/src/pulsecore/source-output.c
+++ b/src/pulsecore/source-output.c
@@ -127,7 +127,7 @@ pa_source_output* pa_source_output_new(
         if (pa_channel_map_compatible(&data->source->channel_map, &data->sample_spec))
             data->channel_map = data->source->channel_map;
         else
-            pa_return_null_if_fail(pa_channel_map_init_auto(&data->channel_map, data->sample_spec.channels, PA_CHANNEL_MAP_DEFAULT));
+            pa_channel_map_init_extend(&data->channel_map, data->sample_spec.channels, PA_CHANNEL_MAP_DEFAULT);
     }
 
     pa_return_null_if_fail(pa_channel_map_valid(&data->channel_map));