diff --git a/docs/handbook/concepts.rst b/docs/handbook/concepts.rst
index 055821a15..8f4373fff 100644
--- a/docs/handbook/concepts.rst
+++ b/docs/handbook/concepts.rst
@@ -25,9 +25,9 @@ Modes
 -----
 
 The ``mode`` of an image defines the type and depth of a pixel in the image.
-Each pixel uses the full range of the bit depth. So a 1-bit pixel has a range
-of 0-1, an 8-bit pixel has a range of 0-255 and so on. The current release
-supports the following standard modes:
+A 1-bit pixel has a range of 0-1, an 8-bit pixel or a 32-bit floating point
+pixel has a range of 0-255, and a 32-bit signed integer has a range of 0-65535.
+The current release supports the following standard modes:
 
     * ``1`` (1-bit pixels, black and white, stored with one pixel per byte)
     * ``L`` (8-bit pixels, black and white)