diff --git a/components/style/properties/longhand/pointing.mako.rs b/components/style/properties/longhand/pointing.mako.rs
index 562e756cec6..27d709567e8 100644
--- a/components/style/properties/longhand/pointing.mako.rs
+++ b/components/style/properties/longhand/pointing.mako.rs
@@ -55,6 +55,9 @@
 // TODO(pcwalton): SVG-only values.
 ${helpers.single_keyword("pointer-events", "auto none")}
 
+${helpers.single_keyword("-moz-user-modify", "read-only read-write write-only", products="gecko",
+                         gecko_ffi_name="mUserModify", gecko_constant_prefix="NS_STYLE_USER_MODIFY")}
+
 ${helpers.single_keyword("-moz-user-focus",
                          "ignore normal select-after select-before select-menu select-same select-all none",
                          products="gecko",