diff --git a/code/rend2/tr_shade.c b/code/rend2/tr_shade.c
index f0bcd7f8..6698b41b 100644
--- a/code/rend2/tr_shade.c
+++ b/code/rend2/tr_shade.c
@@ -1179,7 +1179,7 @@ static void RB_FogPass( void ) {
 	{
 		int index = 0;
 
-		if (deformGen |= DGEN_NONE)
+		if (deformGen != DGEN_NONE)
 			index |= FOGDEF_USE_DEFORM_VERTEXES;
 
 		if (glState.vertexAttribsInterpolation)