diff --git a/helgrind/hg_errors.c b/helgrind/hg_errors.c
index 1d1acc2..8a7ebe1 100644
--- a/helgrind/hg_errors.c
+++ b/helgrind/hg_errors.c
@@ -1006,7 +1006,7 @@
 #  undef TRY
 }
 
-Bool HG_(read_extra_suppression_info) ( Int fd, Char* buf, Int nBuf,
+Bool HG_(read_extra_suppression_info) ( Int fd, Char** bufpp, SizeT* nBufp,
                                         Supp* su )
 {
    /* do nothing -- no extra suppression info present.  Return True to