--- a/layout/generic/nsIFrame.h
+++ b/layout/generic/nsIFrame.h
@@ -363,21 +363,19 @@ private:
   bool mNextInFlowNeedsReflow : 1;
   bool mTruncated : 1;
   bool mFirstLetterComplete : 1;
 };
 
 #define NS_FRAME_SET_TRUNCATION(aStatus, aReflowInput, aMetrics) \
   aStatus.UpdateTruncated(aReflowInput, aMetrics);
 
-#ifdef DEBUG
 // Convert nsReflowStatus to a human-readable string.
 std::ostream&
 operator<<(std::ostream& aStream, const nsReflowStatus& aStatus);
-#endif
 
 //----------------------------------------------------------------------
 
 /**
  * When there is no scrollable overflow rect, the visual overflow rect
  * may be stored as four 1-byte deltas each strictly LESS THAN 0xff, for
  * the four edges of the rectangle, or the four bytes may be read as a
  * single 32-bit "overflow-rect type" value including at least one 0xff