diff --git a/plugins/keyboard/keysrc.l b/plugins/keyboard/keysrc.l
index aba0e7d8..faf796b5 100644
--- a/plugins/keyboard/keysrc.l
+++ b/plugins/keyboard/keysrc.l
@@ -7,7 +7,7 @@ int kparselineno;
 %}
 
 field [A-Za-z0-9][-A-Za-z0-9]*
-number [-0-9]+
+number (-|)[0-9]+
 string \"[^"\n]*\"
 
 %%