diff --git a/src/OpenGL/compiler/OutputASM.cpp b/src/OpenGL/compiler/OutputASM.cpp
index 5495d3f..acd8fbf 100644
--- a/src/OpenGL/compiler/OutputASM.cpp
+++ b/src/OpenGL/compiler/OutputASM.cpp
@@ -2455,7 +2455,7 @@
 
 					dst.type = registerType(left);
 					dst.index += fieldOffset;
-					dst.mask = writeMask(right);
+					dst.mask = writeMask(result);
 
 					return 0xE4;
 				}