Minor documentation issue.
diff --git a/src/truetype/ttgxvar.c b/src/truetype/ttgxvar.c
index ee884ae..7a8c46c 100644
--- a/src/truetype/ttgxvar.c
+++ b/src/truetype/ttgxvar.c
@@ -698,7 +698,8 @@
/* TT_Get_MM_Var initializes the blend structure. */
/* */
/* <Output> */
- /* master :: The `fvar' data (must be freed by caller). */
+ /* master :: The `fvar' data (must be freed by caller). Can be NULL, */
+ /* which makes this function simply load MM support. */
/* */
/* <Return> */
/* FreeType error code. 0 means success. */