diff --git a/src/os/windows/string_uniscribe.cpp b/src/os/windows/string_uniscribe.cpp
--- a/src/os/windows/string_uniscribe.cpp
+++ b/src/os/windows/string_uniscribe.cpp
@@ -106,7 +106,7 @@ public:
 	};
 
 	/** A single line worth of VisualRuns. */
-	class UniscribeLine : public AutoDeleteSmallVector<UniscribeVisualRun *, 4>, public ParagraphLayouter::Line {
+	class UniscribeLine : public AutoDeleteSmallVector<UniscribeVisualRun *>, public ParagraphLayouter::Line {
 	public:
 		virtual int GetLeading() const;
 		virtual int GetWidth() const;