diff --git a/names.tex b/names.tex
index d00088e..29d0dc2 100644
--- a/names.tex
+++ b/names.tex
@@ -61,15 +61,15 @@ upon the length of any component. Package managers should indicate or reject any
 invalid according to the rules below.
 
 A version starts with the number part, which is in the form \t{[0-9]+(\textbackslash.[0-9]+)*}
-(a positive integer, followed by zero or more dot-prefixed positive integers).
+(a non-negative integer, followed by zero or more dot-prefixed non-negative integers).
 
 This may optionally be followed by one of \t{[a-z]} (a lowercase letter).
 
 This may be followed by zero or more of the suffixes \t{_alpha}, \t{_beta}, \t{_pre},
-\t{_rc} or \t{_p}, which themselves may be followed by an optional integer. Suffix and integer
+\t{_rc} or \t{_p}, which themselves may be followed by an optional non-negative integer. Suffix and integer
 count as separate version components.
 
-This may optionally be followed by the suffix \t{-r} followed immediately by an integer (the
+This may optionally be followed by the suffix \t{-r} followed immediately by a non-negative integer (the
 ``revision number''). If this suffix is not present, it is assumed to be \t{-r0}.
 
 \section{Version Comparison}