diff --git a/components/layout/flow.rs b/components/layout/flow.rs
index 74d3100f1f2..a4ea7f884d0 100644
--- a/components/layout/flow.rs
+++ b/components/layout/flow.rs
@@ -409,7 +409,7 @@ pub trait ImmutableFlowUtils {
     fn dump(self);
 
     /// Dumps the flow tree for debugging, with a prefix to indicate that we're at the given level.
-    fn dump_with_level(self, level: uint);
+    fn dump_with_level(self, level: u32);
 }
 
 pub trait MutableFlowUtils {
@@ -1195,7 +1195,7 @@ impl<'a> ImmutableFlowUtils for &'a (Flow + 'a) {
     }
 
     /// Dumps the flow tree for debugging, with a prefix to indicate that we're at the given level.
-    fn dump_with_level(self, level: uint) {
+    fn dump_with_level(self, level: u32) {
         let mut indent = String::new();
         for _ in range(0, level) {
             indent.push_str("| ")