--- a/servo/components/style/properties/longhand/column.mako.rs
+++ b/servo/components/style/properties/longhand/column.mako.rs
@@ -58,16 +58,17 @@
     extra_prefixes="moz",
     ignored_when_colors_disabled=True,
     spec="https://drafts.csswg.org/css-multicol/#propdef-column-rule-color",
 )}
 
 ${helpers.single_keyword("column-span", "none all",
                          products="gecko", animation_value_type="discrete",
                          gecko_pref="layout.css.column-span.enabled",
-                         spec="https://drafts.csswg.org/css-multicol/#propdef-column-span")}
+                         spec="https://drafts.csswg.org/css-multicol/#propdef-column-span",
+                         extra_prefixes="moz")}
 
 ${helpers.single_keyword("column-rule-style",
                          "none hidden dotted dashed solid double groove ridge inset outset",
                          products="gecko", extra_prefixes="moz",
                          gecko_constant_prefix="NS_STYLE_BORDER_STYLE",
                          animation_value_type="discrete",
                          spec="https://drafts.csswg.org/css-multicol/#propdef-column-rule-style")}