diff --git a/lib/nghttp2_hd.c b/lib/nghttp2_hd.c
index c0b185eb..1a0e5a3c 100644
--- a/lib/nghttp2_hd.c
+++ b/lib/nghttp2_hd.c
@@ -259,6 +259,9 @@ static int nghttp2_hd_context_init(nghttp2_hd_context *context,
     return rv;
   }
 
+  context->emit_set = NULL;
+  context->buf_track = NULL;
+
   if(role == NGHTTP2_HD_ROLE_INFLATE) {
     context->emit_set = malloc(sizeof(nghttp2_hd_entry*)*
                                NGHTTP2_INITIAL_EMIT_SET_SIZE);