diff --git a/basisu_tool.cpp b/basisu_tool.cpp
index 3fbc56a..44eb154 100644
--- a/basisu_tool.cpp
+++ b/basisu_tool.cpp
@@ -52,11 +52,11 @@ static void print_usage()
 	printf("\nUsage: basisu filename [filename ...] <options>\n");
 	
 	puts("\n"
-		"The default mode is compression of one or more PNG files to a .basis file. Alternate modes:\n"
+		"The default mode is compression of one or more PNG/BMP files to a .basis file. Alternate modes:\n"
 		" -unpack: Use transcoder to unpack .basis file to one or more .ktx/.png files\n"
 		" -validate: Validate and display information about a .basis file\n"
 		" -info: Display high-level information about a .basis file\n"
-		" -compare: Compare two PNG images specified with -file, output PSNR and SSIM statistics and RGB/A delta images\n"
+		" -compare: Compare two PNG/BMP images specified with -file, output PSNR and SSIM statistics and RGB/A delta images\n"
 		" -version: Print basisu version and exit\n"
 		"Unless an explicit mode is specified, if one or more files have the .basis extension this tool defaults to unpack mode.\n"
 		"\n"
@@ -66,8 +66,8 @@ static void print_usage()
 		"Filenames prefixed with a @ symbol are read as filename listing files. Listing text files specify which actual filenames to process (one filename per line).\n"
 		"\n"
 		"Options:\n"
-		" -file filename.png: Input image filename, multiple images are OK, use -file X for each input filename (prefixing input filenames with -file is optional)\n"
-		" -alpha_file filename.png: Input alpha image filename, multiple images are OK, use -file X for each input filename (must be paired with -file), images converted to REC709 grayscale and used as input alpha\n"
+		" -file filename.png/bmp: Input image filename, multiple images are OK, use -file X for each input filename (prefixing input filenames with -file is optional)\n"
+		" -alpha_file filename.png/bmp: Input alpha image filename, multiple images are OK, use -file X for each input filename (must be paired with -file), images converted to REC709 grayscale and used as input alpha\n"
 		" -multifile_printf: printf() format strint to use to compose multiple filenames\n"
 		" -multifile_first: The index of the first file to process, default is 0 (must specify -multifile_printf and -multifile_num)\n"
 		" -multifile_num: The total number of files to process.\n"