--- a/servo/components/style/dom.rs
+++ b/servo/components/style/dom.rs
@@ -254,16 +254,28 @@ pub trait TElement : PartialEq + Debug +
     /// Get this element's style attribute.
     fn style_attribute(&self) -> Option<&Arc<RwLock<PropertyDeclarationBlock>>>;
 
     /// Get this element's animation rules.
     fn get_animation_rules(&self, _pseudo: Option<&PseudoElement>) -> AnimationRules {
         AnimationRules(None, None)
     }
 
+    /// Get this element's animation rule.
+    fn get_animation_rule(&self, _pseudo: Option<&PseudoElement>)
+                          -> Option<Arc<RwLock<PropertyDeclarationBlock>>> {
+        None
+    }
+
+    /// Get this element's transition rule.
+    fn get_transition_rule(&self, _pseudo: Option<&PseudoElement>)
+                           -> Option<Arc<RwLock<PropertyDeclarationBlock>>> {
+        None
+    }
+
     /// Get this element's state, for non-tree-structural pseudos.
     fn get_state(&self) -> ElementState;
 
     /// Whether this element has an attribute with a given namespace.
     fn has_attr(&self, namespace: &Namespace, attr: &LocalName) -> bool;
 
     /// Whether an attribute value equals `value`.
     fn attr_equals(&self, namespace: &Namespace, attr: &LocalName, value: &Atom) -> bool;

--- a/servo/components/style/gecko/wrapper.rs
+++ b/servo/components/style/gecko/wrapper.rs
@@ -411,22 +411,30 @@ impl<'le> TElement for GeckoElement<'le>
     }
 
     fn style_attribute(&self) -> Option<&Arc<RwLock<PropertyDeclarationBlock>>> {
         let declarations = unsafe { Gecko_GetStyleAttrDeclarationBlock(self.0) };
         declarations.map(|s| s.as_arc_opt()).unwrap_or(None)
     }
 
     fn get_animation_rules(&self, pseudo: Option<&PseudoElement>) -> AnimationRules {
+        AnimationRules(self.get_animation_rule(pseudo),
+                       self.get_transition_rule(pseudo))
+    }
+
+    fn get_animation_rule(&self, pseudo: Option<&PseudoElement>)
+                          -> Option<Arc<RwLock<PropertyDeclarationBlock>>> {
         let atom_ptr = PseudoElement::ns_atom_or_null_from_opt(pseudo);
-        unsafe {
-            AnimationRules(
-                Gecko_GetAnimationRule(self.0, atom_ptr, CascadeLevel::Animations).into_arc_opt(),
-                Gecko_GetAnimationRule(self.0, atom_ptr, CascadeLevel::Transitions).into_arc_opt())
-        }
+        unsafe { Gecko_GetAnimationRule(self.0, atom_ptr, CascadeLevel::Animations).into_arc_opt() }
+    }
+
+    fn get_transition_rule(&self, pseudo: Option<&PseudoElement>)
+                           -> Option<Arc<RwLock<PropertyDeclarationBlock>>> {
+        let atom_ptr = PseudoElement::ns_atom_or_null_from_opt(pseudo);
+        unsafe { Gecko_GetAnimationRule(self.0, atom_ptr, CascadeLevel::Transitions).into_arc_opt() }
     }
 
     fn get_state(&self) -> ElementState {
         unsafe {
             ElementState::from_bits_truncate(Gecko_ElementState(self.0))
         }
     }