diff --git a/docs/cmake-functions.md b/docs/cmake-functions.md
index 3b2c381..0efdb20 100644
--- a/docs/cmake-functions.md
+++ b/docs/cmake-functions.md
@@ -337,7 +337,8 @@ The following variables should be set before calling `dmod_add_executable` or `d
 - `DMOD_COMPRESSION_METHOD` - Compression method for DMFC files (default: "fastlz")
 - `DMOD_ASSETS_PATHS` - List of directories with the sources of a module's assets (views, images, fonts). When set, they are converted into `DMOD_VIEWS_DIR` (default: `<build>/views`) by the `dmod_assets` target, which the module depends on - with tools `dmf-get` downloads at configure time, only for the kinds of files found:
   - `*.dmvs` views - `todmv` - `<name>.dmv`;
-  - images (`DMOD_IMAGE_EXTENSIONS`, default `png jpg jpeg jpe jfif bmp qoi gif tif tiff`) - `todmvi` with the `dmimg` decoder of each extension (`dmimg_png`, `dmimg_jpeg` for `.jpg`, ...; `DMOD_IMAGE_DECODERS` overrides the list) - `<name>.dmvi`, next to the views, so a view finds them by name. An optional `<image>.ini` next to an image (`logo.png.ini`) sets its conversion: `format` (`auto`, `rgb565`, `rgb565a8`, `argb8888`, `i8`, `a8`, `a4`), `size` (`WIDTHxHEIGHT`, scaled down to fit), `compression` (`fastlz`, `none`), `dither` (`on`/`off`). Keys before any section apply to every output; each `[section]` is an output `<section>.dmvi` of its own (e.g. `[logo]` and `[logo-mask]` from one image).   - fonts (`DMOD_FONT_EXTENSIONS`, default `ttf otf ttc`) - `todmvf` - `.dmvf`, next to the views. A font needs its `<font>.ini` (`Roboto-Regular.ttf.ini`), as a font is made for one pixel size: each `[section]` is an output `<section>.dmvf` with its `size` (pixel size, `4` ... `127`, required) and optional `chars` (codepoint ranges, e.g. `0x20-0x7E,0x104`; default: printable ASCII, Latin-1, Latin Extended-A). A font without an `.ini` is left out with a warning.
+  - images (`DMOD_IMAGE_EXTENSIONS`, default `png jpg jpeg jpe jfif bmp qoi gif tif tiff`) - `todmvi` with the `dmimg` decoder of each extension (`dmimg_png`, `dmimg_jpeg` for `.jpg`, ...; `DMOD_IMAGE_DECODERS` overrides the list) - `<name>.dmvi`, next to the views, so a view finds them by name. An optional `<image>.ini` next to an image (`logo.png.ini`) sets its conversion: `format` (`auto`, `rgb565`, `rgb565a8`, `argb8888`, `i8`, `a8`, `a4`), `size` (`WIDTHxHEIGHT`, scaled down to fit), `compression` (`fastlz`, `none`), `dither` (`on`/`off`). Keys before any section apply to every output; each `[section]` is an output `<section>.dmvi` of its own (e.g. `[logo]` and `[logo-mask]` from one image).
+  - fonts (`DMOD_FONT_EXTENSIONS`, default `ttf otf ttc`) - `todmvf` - `.dmvf`, next to the views. A font needs its `<font>.ini` (`Roboto-Regular.ttf.ini`), as a font is made for one pixel size: each `[section]` is an output `<section>.dmvf` with its `size` (pixel size, `4` ... `127`, required) and optional `chars` (codepoint ranges, e.g. `0x20-0x7E,0x104`; default: printable ASCII, Latin-1, Latin Extended-A) and `tracking` (letter spacing added to every advance, in pixels, e.g. `-2.4`, like CSS `letter-spacing`). A font without an `.ini` is left out with a warning.
 
   Two sources of one output name are a configuration error.
 
diff --git a/scripts/CMakeLists.txt b/scripts/CMakeLists.txt
index e1d5209..47f9d08 100644
--- a/scripts/CMakeLists.txt
+++ b/scripts/CMakeLists.txt
@@ -213,6 +213,8 @@ endfunction()
 #   size        = pixel size (em), 4 ... 127 - required
 #   chars       = codepoint ranges, e.g. 0x20-0x7E,0x104 (default: printable
 #                 ASCII, Latin-1, Latin Extended-A)
+#   tracking    = letter spacing added to every advance, pixels, e.g. -2.4
+#                 (CSS letter-spacing; default 0)
 #
 # Related variables:
 #   DMOD_VIEWS_DIR          output directory of the converted assets
@@ -296,8 +298,13 @@ function(_dmod_font_option iniPath key value outVar)
     set(ARGS "")
     if(key STREQUAL "chars")
         set(ARGS -c ${value})
+    elseif(key STREQUAL "tracking")
+        if(NOT value MATCHES "^[-+]?[0-9]+(\\.[0-9]+)?$")
+            message(SEND_ERROR "${iniPath}: tracking must be a number of pixels, e.g. -2.4 (got '${value}')")
+        endif()
+        set(ARGS -t ${value})
     else()
-        message(SEND_ERROR "${iniPath}: unknown key '${key}' (size, chars)")
+        message(SEND_ERROR "${iniPath}: unknown key '${key}' (size, chars, tracking)")
     endif()
     set(${outVar} "${ARGS}" PARENT_SCOPE)
 endfunction()