diff --git a/tools/skpdiff/SkCLImageDiffer.cpp b/tools/skpdiff/SkCLImageDiffer.cpp
index d1e6958..b99ef40 100644
--- a/tools/skpdiff/SkCLImageDiffer.cpp
+++ b/tools/skpdiff/SkCLImageDiffer.cpp
@@ -84,7 +84,7 @@
     return true;
 }
 
-bool SkCLImageDiffer::makeImage2D(SkBitmap* bitmap, cl_mem* image) {
+bool SkCLImageDiffer::makeImage2D(SkBitmap* bitmap, cl_mem* image) const {
     cl_int imageErr;
     cl_image_format bitmapFormat;
     switch (bitmap->config()) {