diff --git a/reference/constraints/NotBlank.rst b/reference/constraints/NotBlank.rst
index 8de6034b48c..a7ef539c92c 100644
--- a/reference/constraints/NotBlank.rst
+++ b/reference/constraints/NotBlank.rst
@@ -1,8 +1,8 @@
 NotBlank
 ========
 
-Validates that a value is not blank, defined as not equal to a blank string
-and also not equal to ``null``. To force that a value is simply not equal to
+Validates that a value is not blank, defined as not strictly ``false``, not equal to a blank
+string and also not equal to ``null``. To force that a value is simply not equal to
 ``null``, see the :doc:`/reference/constraints/NotNull` constraint.
 
 +----------------+------------------------------------------------------------------------+