diff --git a/src/shrpx_downstream.cc b/src/shrpx_downstream.cc
index 64508033..44f5db9e 100644
--- a/src/shrpx_downstream.cc
+++ b/src/shrpx_downstream.cc
@@ -360,7 +360,7 @@ void append_last_header_key(bool key_prev, size_t &sum, Headers &headers,
 namespace {
 void append_last_header_value(bool key_prev, size_t &sum, Headers &headers,
                               const char *data, size_t len) {
-  assert(!key_prev);
+  key_prev = false;
   sum += len;
   auto &item = headers.back();
   item.value.append(data, len);
@@ -455,11 +455,6 @@ void FieldStore::add_header(std::string name, std::string value) {
                     std::move(value));
 }
 
-void FieldStore::set_last_header_value(const char *data, size_t len) {
-  shrpx::set_last_header_value(header_key_prev_, buffer_size_, headers_, data,
-                               len);
-}
-
 void FieldStore::add_header(std::string name, std::string value,
                             int16_t token) {
   http2::index_header(hdidx_, token, headers_.size());
@@ -504,11 +499,6 @@ void FieldStore::add_trailer(std::string name, std::string value) {
                     std::move(value));
 }
 
-void FieldStore::set_last_trailer_value(const char *data, size_t len) {
-  shrpx::set_last_header_value(trailer_key_prev_, buffer_size_, trailers_, data,
-                               len);
-}
-
 void FieldStore::append_last_trailer_key(const char *data, size_t len) {
   shrpx::append_last_header_key(trailer_key_prev_, buffer_size_, trailers_,
                                 data, len);
diff --git a/src/shrpx_downstream.h b/src/shrpx_downstream.h
index b4d84d79..b13c27e4 100644
--- a/src/shrpx_downstream.h
+++ b/src/shrpx_downstream.h
@@ -84,7 +84,6 @@ public:
 
   void append_last_header_key(const char *data, size_t len);
   void append_last_header_value(const char *data, size_t len);
-  void set_last_header_value(const char *data, size_t len);
 
   bool header_key_prev() const { return header_key_prev_; }
 
@@ -103,8 +102,6 @@ public:
   void append_last_trailer_key(const char *data, size_t len);
   void append_last_trailer_value(const char *data, size_t len);
 
-  void set_last_trailer_value(const char *data, size_t len);
-
   bool trailer_key_prev() const { return trailer_key_prev_; }
 
   // content-length, -1 if it is unknown.
diff --git a/src/shrpx_https_upstream.cc b/src/shrpx_https_upstream.cc
index 772df751..3d9bdc2d 100644
--- a/src/shrpx_https_upstream.cc
+++ b/src/shrpx_https_upstream.cc
@@ -179,17 +179,9 @@ int htp_hdr_valcb(http_parser *htp, const char *data, size_t len) {
     return -1;
   }
   if (downstream->get_request_state() == Downstream::INITIAL) {
-    if (req.fs.header_key_prev()) {
-      req.fs.set_last_header_value(data, len);
-    } else {
-      req.fs.append_last_header_value(data, len);
-    }
+    req.fs.append_last_header_value(data, len);
   } else {
-    if (req.fs.trailer_key_prev()) {
-      req.fs.set_last_trailer_value(data, len);
-    } else {
-      req.fs.append_last_trailer_value(data, len);
-    }
+    req.fs.append_last_trailer_value(data, len);
   }
   return 0;
 }