diff --git a/src/http_ana.c b/src/http_ana.c
index beee63c6c..6b2d7f0f3 100644
--- a/src/http_ana.c
+++ b/src/http_ana.c
@@ -2522,10 +2522,11 @@ int http_replace_hdrs(struct stream* s, struct htx *htx, struct ist name,
 		     const char *str, struct my_regex *re, int full)
 {
 	struct http_hdr_ctx ctx;
-	struct buffer *output = get_trash_chunk();
 
 	ctx.blk = NULL;
 	while (http_find_header(htx, name, &ctx, full)) {
+		struct buffer *output = get_trash_chunk();
+
 		if (!regex_exec_match2(re, ctx.value.ptr, ctx.value.len, MAX_MATCH, pmatch, 0))
 			continue;