diff --git a/PVRTCEncoder/src/Image.h b/PVRTCEncoder/src/Image.h
index eabc045..8550d2a 100644
--- a/PVRTCEncoder/src/Image.h
+++ b/PVRTCEncoder/src/Image.h
@@ -69,7 +69,7 @@ class Image {
   ~Image();
 
   void BilinearUpscale(uint32 xtimes, uint32 ytimes,
-                       EWrapMode wrapMode = eWrapMode_Clamp);
+                       EWrapMode wrapMode = eWrapMode_Wrap);
   void ChangeBitDepth(const uint8 (&depths)[4]);
   void ExpandTo8888();
 
diff --git a/PVRTCEncoder/test/ImageTest.cpp b/PVRTCEncoder/test/ImageTest.cpp
index d48a195..e16d622 100644
--- a/PVRTCEncoder/test/ImageTest.cpp
+++ b/PVRTCEncoder/test/ImageTest.cpp
@@ -131,7 +131,7 @@ TEST(Image, BilinearUpscale) {
   }
 
   PVRTCC::Image img(4, 4, pxs);
-  img.BilinearUpscale(1, 1);
+  img.BilinearUpscale(1, 1, PVRTCC::eWrapMode_Clamp);
   EXPECT_EQ(img.GetWidth(), static_cast<uint32>(8));
   EXPECT_EQ(img.GetHeight(), static_cast<uint32>(8));
 
@@ -171,7 +171,7 @@ TEST(Image, BilinearUpscaleMaintainsPixels) {
   }
 
   PVRTCC::Image img(w, h, pxs);
-  img.BilinearUpscale(2, 2);
+  img.BilinearUpscale(2, 2, PVRTCC::eWrapMode_Clamp);
   EXPECT_EQ(img.GetWidth(), w << 2);
   EXPECT_EQ(img.GetHeight(), h << 2);
 
@@ -199,7 +199,7 @@ TEST(Image, NonuniformBilinearUpscale) {
   }
 
   PVRTCC::Image img(kHeight, kWidth, pxs);
-  img.BilinearUpscale(2, 1);
+  img.BilinearUpscale(2, 1, PVRTCC::eWrapMode_Clamp);
   EXPECT_EQ(img.GetWidth(), static_cast<uint32>(kWidth << 2));
   EXPECT_EQ(img.GetHeight(), static_cast<uint32>(kHeight << 1));