diff --git a/src/libstd/bitflags.rs b/src/libstd/bitflags.rs
index 3d1bc20cca49ecd0870bab4346977e0260b370b0..8af88b4fe7247a5257f241006af027eb23efc870 100644
--- a/src/libstd/bitflags.rs
+++ b/src/libstd/bitflags.rs
@@ -170,6 +170,7 @@ pub fn intersects(&self, other: $BitFlags) -> bool {
             }
 
             /// Returns `true` all of the flags in `other` are contained within `self`.
+            #[inline]
             pub fn contains(&self, other: $BitFlags) -> bool {
                 (self & other) == other
             }