diff --git a/src/flt_http_comp.c b/src/flt_http_comp.c
index ce0dba17c..380366b06 100644
--- a/src/flt_http_comp.c
+++ b/src/flt_http_comp.c
@@ -255,10 +255,12 @@ comp_http_payload(struct stream *s, struct filter *filter, struct http_msg *msg,
 					}
 					if (htx_compression_buffer_end(st, &trash, 1) < 0)
 						goto error;
-					blk = htx_add_data_before(htx, blk, ist2(b_head(&trash), b_data(&trash)));
-					if (!blk)
-						goto error;
-					to_forward += b_data(&trash);
+					if (b_data(&trash)) {
+						blk = htx_add_data_before(htx, blk, ist2(b_head(&trash), b_data(&trash)));
+						if (!blk)
+							goto error;
+						to_forward += b_data(&trash);
+					}
 					msg->flags &= ~HTTP_MSGF_COMPRESSING;
 					/* We let the mux add last empty chunk and empty trailers */
 				}