--- a/layout/style/ServoStyleSetInlines.h
+++ b/layout/style/ServoStyleSetInlines.h
@@ -5,22 +5,26 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #ifndef mozilla_ServoStyleSetInlines_h
 #define mozilla_ServoStyleSetInlines_h
 
 #include "mozilla/ServoStyleSet.h"
 #include "mozilla/ServoBindings.h"
 
+namespace mozilla {
+
 nscoord
 ServoStyleSet::EvaluateSourceSizeList(
   const RawServoSourceSizeList* aSourceSizeList) const
 {
   return Servo_SourceSizeList_Evaluate(mRawSet.get(), aSourceSizeList);
 }
 
 already_AddRefed<ComputedStyle>
 ServoStyleSet::ResolveServoStyle(dom::Element* aElement)
 {
   return Servo_ResolveStyle(aElement, mRawSet.get()).Consume();
 }
 
+} // namespace mozilla
+
 #endif // mozilla_ServoStyleSetInlines_h