diff --git a/src/image.cpp b/src/image.cpp
index 4114fedc..2f3c79ff 100644
--- a/src/image.cpp
+++ b/src/image.cpp
@@ -445,7 +445,7 @@ namespace bgfx
 	static const int32_t s_etc1Mod[8][4] =
 	{
 		{  2,   8,  -2,   -8},
-		{ 15,  17, -15,  -17},
+		{  5,  17,  -5,  -17},
 		{  9,  29,  -9,  -29},
 		{ 13,  42, -13,  -42},
 		{ 18,  60, -18,  -60},