--- a/servo/components/style/properties/gecko.mako.rs
+++ b/servo/components/style/properties/gecko.mako.rs
@@ -2034,16 +2034,25 @@ fn static_assert() {
     }
 
     pub fn copy_quotes_from(&mut self, other: &Self) {
         unsafe { self.gecko.mQuotes.set(&other.gecko.mQuotes); }
     }
 
 </%self:impl_trait>
 
+<%self:impl_trait style_struct_name="Table" skip_longhands="-x-span">
+    #[allow(non_snake_case)]
+    pub fn set__x_span(&mut self, v: longhands::_x_span::computed_value::T) {
+        self.gecko.mSpan = v.0
+    }
+
+    ${impl_simple_copy('_x_span', 'mSpan')}
+</%self:impl_trait>
+
 <%self:impl_trait style_struct_name="Effects"
                   skip_longhands="box-shadow filter">
     pub fn set_box_shadow(&mut self, v: longhands::box_shadow::computed_value::T) {
         use cssparser::Color;
 
         self.gecko.mBoxShadow.replace_with_new(v.0.len() as u32);
 
         for (servo, gecko_shadow) in v.0.into_iter()

--- a/servo/components/style/properties/longhand/table.mako.rs
+++ b/servo/components/style/properties/longhand/table.mako.rs
@@ -4,8 +4,43 @@
 
 <%namespace name="helpers" file="/helpers.mako.rs" />
 
 <% data.new_style_struct("Table", inherited=False) %>
 
 ${helpers.single_keyword("table-layout", "auto fixed",
                          gecko_ffi_name="mLayoutStrategy", animatable=False,
                          spec="https://drafts.csswg.org/css-tables/#propdef-table-layout")}
+
+<%helpers:longhand name="-x-span" products="gecko"
+                   spec="Internal-only (for `<col span>` pres attr)"
+                   animatable="False"
+                   internal="True">
+    use values::HasViewportPercentage;
+    use values::computed::ComputedValueAsSpecified;
+
+    impl ComputedValueAsSpecified for SpecifiedValue {}
+    no_viewport_percentage!(SpecifiedValue);
+    pub type SpecifiedValue = computed_value::T;
+    pub mod computed_value {
+        use std::fmt;
+        use style_traits::ToCss;
+
+        #[derive(PartialEq, Clone, Copy, Debug)]
+        pub struct T(pub i32);
+
+        impl ToCss for T {
+            fn to_css<W>(&self, _: &mut W) -> fmt::Result where W: fmt::Write {
+                Ok(())
+            }
+        }
+    }
+
+    #[inline]
+    pub fn get_initial_value() -> computed_value::T {
+        computed_value::T(1)
+    }
+
+    // never parse it, only set via presentation attribute
+    fn parse(_: &ParserContext, _: &mut Parser) -> Result<SpecifiedValue, ()> {
+        Err(())
+    }
+</%helpers:longhand>

--- a/servo/ports/geckolib/glue.rs
+++ b/servo/ports/geckolib/glue.rs
@@ -1056,20 +1056,28 @@ pub extern "C" fn Servo_DeclarationBlock
         BorderRightStyle => BorderStyle::from_gecko_keyword(value),
         BorderBottomStyle => BorderStyle::from_gecko_keyword(value),
         BorderLeftStyle => BorderStyle::from_gecko_keyword(value),
     };
     declarations.write().declarations.push((prop, Default::default()));
 }
 
 #[no_mangle]
-pub extern "C" fn Servo_DeclarationBlock_SetIntValue(_: RawServoDeclarationBlockBorrowed,
-                                                     _: nsCSSPropertyID,
-                                                     _: i32) {
-    error!("stylo: Don't know how to handle integer presentation attributes (-x-span)");
+pub extern "C" fn Servo_DeclarationBlock_SetIntValue(declarations: RawServoDeclarationBlockBorrowed,
+                                                     property: nsCSSPropertyID,
+                                                     value: i32) {
+    use style::properties::{DeclaredValue, PropertyDeclaration, LonghandId};
+    use style::properties::longhands::_x_span::computed_value::T as Span;
+
+    let declarations = RwLock::<PropertyDeclarationBlock>::as_arc(&declarations);
+    let long = get_longhand_from_id!(property);
+    let prop = match_wrap_declared! {long,
+        XSpan => Span(value),
+    };
+    declarations.write().declarations.push((prop, Default::default()));
 }
 
 #[no_mangle]
 pub extern "C" fn Servo_DeclarationBlock_SetPixelValue(declarations:
                                                        RawServoDeclarationBlockBorrowed,
                                                        property: nsCSSPropertyID,
                                                        value: f32) {
     use style::properties::{DeclaredValue, PropertyDeclaration, LonghandId};