diff --git a/bytebeat_compiler.py b/bytebeat_compiler.py
index a8eec5b..c820793 100644
--- a/bytebeat_compiler.py
+++ b/bytebeat_compiler.py
@@ -143,7 +143,7 @@ if __name__ == "__main__":
 	parser.add_argument("file", type=str,
 		help="bytebeat formula file (use `-` to read from stdin)")
 	parser.add_argument("-o", "--output", default="output.wav", type=str,
-		help="specify output file path (default is `output.wav`")
+		help="specify output WAVE file path (default is `output.wav`")
 	parser.add_argument("-r", "--sample-rate", default=8000, type=int,
 		help="sample rate (Hz)")
 	parser.add_argument("-p", "--final-sample-rate", default=None, type=int,