diff --git a/src/gallium/auxiliary/vl/vl_csc.c b/src/gallium/auxiliary/vl/vl_csc.c
index c8efe286755..1587e6cf1df 100644
--- a/src/gallium/auxiliary/vl/vl_csc.c
+++ b/src/gallium/auxiliary/vl/vl_csc.c
@@ -59,10 +59,10 @@
  * [ 0, 0, 0, 1]
  *
  * brightness
- * [ 1, 0, 0, b]
- * [ 0, 1, 0, 0]
- * [ 0, 0, 1, 0]
- * [ 0, 0, 0, 1]
+ * [ 1, 0, 0, b/c]
+ * [ 0, 1, 0,   0]
+ * [ 0, 0, 1,   0]
+ * [ 0, 0, 0,   1]
  *
  * saturation
  * [ 1, 0, 0, 0]