diff --git a/src/nvtt/InputOptions.cpp b/src/nvtt/InputOptions.cpp
index ba3934e..04861cd 100644
--- a/src/nvtt/InputOptions.cpp
+++ b/src/nvtt/InputOptions.cpp
@@ -337,6 +337,12 @@ void InputOptions::setNormalizeMipmaps(bool normalize)
     m.normalizeMipmaps = normalize;
 }
 
+// Set linear transform for the given channel.
+// Stub for ABI compatibily, never implemented
+void InputOptions::setLinearTransform(int, float, float, float, float)
+{
+}
+
 void InputOptions::setMaxExtents(int e)
 {
     nvDebugCheck(e > 0);
diff --git a/src/nvtt/nvtt.h b/src/nvtt/nvtt.h
index 6a5a8a3..b3b6166 100644
--- a/src/nvtt/nvtt.h
+++ b/src/nvtt/nvtt.h
@@ -322,6 +322,9 @@ namespace nvtt
         NVTT_API void setNormalFilter(float sm, float medium, float big, float large);
         NVTT_API void setNormalizeMipmaps(bool b);
 
+        // Set color transforms.
+        NVTT_API void setLinearTransform(int channel, float w0, float w1, float w2, float w3);
+
         // Set resizing options.
         NVTT_API void setMaxExtents(int d);
         NVTT_API void setRoundMode(RoundMode mode);