diff --git a/doc/source/user_guide/data_types.txt b/doc/source/user_guide/data_types.txt
index 7ce032f1..5ecada3c 100644
--- a/doc/source/user_guide/data_types.txt
+++ b/doc/source/user_guide/data_types.txt
@@ -8,18 +8,22 @@ data types [1]_, *i.e.* "dtypes". To avoid distorting image intensities (see
 `Rescaling intensity values`_), we assume that images use the following dtype
 ranges:
 
-=========  ===============
+=========  ===============================
 Data type  Range
-=========  ===============
+=========  ===============================
 uint8      0 to 255
 uint16     0 to 65535
+uint32     0 to 2\ :sup:`32`
 float      0 to 1
 int8       -128 to 127
 int16      -32768 to 32767
-=========  ===============
+int32      -2\ :sup:`31` to 2\ :sup:`31`-1
+=========  ===============================
 
 Note that float images are restricted to the range 0 to 1 even though the data
-type itself can exceed this range.
+type itself can exceed this range; all integer dtypes, on the other hand, have
+pixel intensities that can span the entire data type range. Currently, *64-bit
+(u)int images are not supported*.
 
 Functions in ``skimage`` are designed so that they accept any of these dtypes,
 but, for efficiency, *may return an image of a different dtype* (see `Output