diff --git a/src/pdf2htmlEX.cc b/src/pdf2htmlEX.cc
index 3a82ed5..8bec400 100644
--- a/src/pdf2htmlEX.cc
+++ b/src/pdf2htmlEX.cc
@@ -63,8 +63,8 @@ void parse_options (int argc, char **argv)
.add("last-page,l", ¶m.last_page, numeric_limits::max(), "last page to process")
.add("zoom", ¶m.zoom, 0, "zoom ratio", nullptr, true)
- .add("fit-width", ¶m.fit_width, 0, "fit width", nullptr, true)
- .add("fit-height", ¶m.fit_height, 0, "fit height", nullptr, true)
+ .add("fit-width", ¶m.fit_width, 0, "fit width to pixels", nullptr, true)
+ .add("fit-height", ¶m.fit_height, 0, "fit height to pixels", nullptr, true)
.add("hdpi", ¶m.h_dpi, 144.0, "horizontal DPI for non-text")
.add("vdpi", ¶m.v_dpi, 144.0, "vertical DPI for non-text")
.add("use-cropbox", ¶m.use_cropbox, 0, "use CropBox instead of MediaBox")