diff --git a/lib/src/phy/channel/test/awgn_channel_test.c b/lib/src/phy/channel/test/awgn_channel_test.c
index 77216908f..400508287 100644
--- a/lib/src/phy/channel/test/awgn_channel_test.c
+++ b/lib/src/phy/channel/test/awgn_channel_test.c
@@ -277,6 +277,9 @@ clean_exit:
   if (output_buffer) {
     free(output_buffer);
   }
+  if (help_buffer) {
+    free(help_buffer);
+  }
 
 #ifdef ENABLE_GUI
   if (fft_out) {