diff --git a/INSTALL.in b/INSTALL.in
index 03ea4bbbd3..6fc8f25736 100644
--- a/INSTALL.in
+++ b/INSTALL.in
@@ -165,7 +165,7 @@ header files installed.
      libXcursor		-		X11 Mouse Cursor
      libxpm		-		XPM
      ExcHndl		-		Crash logs on Windows with Dr. MinGW
-     libwebp		@WEBP_REQUIRED_VERSION@		WebP
+     libwebp		@WEBP_REQUIRED_VERSION@		WebP (built with --enable-libwebpmux and --enable-libwebpdemux)
 
  19. Summary of optional runtime dependencies: