diff --git a/doc/filters.texi b/doc/filters.texi
index 57189c77b0..e26dde4b1a 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -11711,7 +11711,8 @@ can be used to test the monowhite pixel format descriptor definition.
 
 @section pixscope
 
-Display sample values of color channels. Mainly useful for checking color and levels.
+Display sample values of color channels. Mainly useful for checking color
+and levels. Minimum supported resolution is 640x480.
 
 The filters accept the following options: