diff --git a/src/utils/SkPatchUtils.cpp b/src/utils/SkPatchUtils.cpp
index 8fafd14..a28abdf 100644
--- a/src/utils/SkPatchUtils.cpp
+++ b/src/utils/SkPatchUtils.cpp
@@ -10,6 +10,7 @@
 #include "SkColorData.h"
 #include "SkGeometry.h"
 #include "SkPM4f.h"
+#include "SkTo.h"
 
 namespace {
     enum CubicCtrlPts {