diff --git a/man/dwebp.1 b/man/dwebp.1
index 9a616763..ba735dbe 100644
--- a/man/dwebp.1
+++ b/man/dwebp.1
@@ -39,7 +39,7 @@ Change the output format to PPM (discards alpha).
 .TP
 .B \-pgm
 Change the output format to PGM. The output consists of luma/chroma
-samples instead of RGB, using the ICM4 layout. This option is mainly
+samples instead of RGB, using the IMC4 layout. This option is mainly
 for verification and debugging purposes.
 .TP
 .B \-yuv