diff --git a/src/shrpx_memcached_connection.cc b/src/shrpx_memcached_connection.cc
index fbae2bbd..d2353897 100644
--- a/src/shrpx_memcached_connection.cc
+++ b/src/shrpx_memcached_connection.cc
@@ -120,7 +120,8 @@ namespace {
 void clear_request(std::deque<std::unique_ptr<MemcachedRequest>> &q) {
   for (auto &req : q) {
     if (req->cb) {
-      req->cb(req.get(), MemcachedResult(MEMCACHED_ERR_EXT_NETWORK_ERROR));
+      req->cb(req.get(),
+              MemcachedResult(MemcachedStatusCode::EXT_NETWORK_ERROR));
     }
   }
   q.clear();
@@ -451,7 +452,8 @@ int MemcachedConnection::parse_packet() {
       parse_state_.extralen = *in++;
       // skip 1 byte reserved data type
       ++in;
-      parse_state_.status_code = util::get_uint16(in);
+      parse_state_.status_code =
+          static_cast<MemcachedStatusCode>(util::get_uint16(in));
       in += 2;
       parse_state_.totalbody = util::get_uint32(in);
       in += 4;
@@ -481,7 +483,8 @@ int MemcachedConnection::parse_packet() {
       }
 
       if (parse_state_.op == MemcachedOp::GET &&
-          parse_state_.status_code == 0 && parse_state_.extralen == 0) {
+          parse_state_.status_code == MemcachedStatusCode::NO_ERROR &&
+          parse_state_.extralen == 0) {
         MCLOG(WARN, this) << "response for GET does not have extra";
         return -1;
       }
@@ -538,9 +541,9 @@ int MemcachedConnection::parse_packet() {
       }
 
       if (LOG_ENABLED(INFO)) {
-        if (parse_state_.status_code) {
-          MCLOG(INFO, this)
-              << "response returned error status: " << parse_state_.status_code;
+        if (parse_state_.status_code != MemcachedStatusCode::NO_ERROR) {
+          MCLOG(INFO, this) << "response returned error status: "
+                            << static_cast<uint16_t>(parse_state_.status_code);
         }
       }
 
diff --git a/src/shrpx_memcached_connection.h b/src/shrpx_memcached_connection.h
index aff76044..2e097e1f 100644
--- a/src/shrpx_memcached_connection.h
+++ b/src/shrpx_memcached_connection.h
@@ -44,6 +44,7 @@ namespace shrpx {
 
 struct MemcachedRequest;
 enum class MemcachedOp : uint8_t;
+enum class MemcachedStatusCode : uint16_t;
 
 enum class MemcachedParseState {
   HEADER24,
@@ -69,7 +70,7 @@ struct MemcachedParseContext {
   // Parser state; see enum above
   MemcachedParseState state;
   // status_code in response
-  int status_code;
+  MemcachedStatusCode status_code;
   // op in response
   MemcachedOp op;
 };
diff --git a/src/shrpx_memcached_result.h b/src/shrpx_memcached_result.h
index a5ac7591..60a87afc 100644
--- a/src/shrpx_memcached_result.h
+++ b/src/shrpx_memcached_result.h
@@ -31,18 +31,18 @@
 
 namespace shrpx {
 
-enum MemcachedStatusCode {
-  MEMCACHED_ERR_NO_ERROR,
-  MEMCACHED_ERR_EXT_NETWORK_ERROR = 0x1001,
+enum class MemcachedStatusCode : uint16_t {
+  NO_ERROR,
+  EXT_NETWORK_ERROR = 0x1001,
 };
 
 struct MemcachedResult {
-  MemcachedResult(int status_code) : status_code(status_code) {}
-  MemcachedResult(int status_code, std::vector<uint8_t> value)
+  MemcachedResult(MemcachedStatusCode status_code) : status_code(status_code) {}
+  MemcachedResult(MemcachedStatusCode status_code, std::vector<uint8_t> value)
       : value(std::move(value)), status_code(status_code) {}
 
   std::vector<uint8_t> value;
-  int status_code;
+  MemcachedStatusCode status_code;
 };
 
 } // namespace shrpx
diff --git a/src/shrpx_tls.cc b/src/shrpx_tls.cc
index 83d89e67..9aa789d0 100644
--- a/src/shrpx_tls.cc
+++ b/src/shrpx_tls.cc
@@ -343,12 +343,14 @@ int tls_session_new_cb(SSL *ssl, SSL_SESSION *session) {
   req->cb = [](MemcachedRequest *req, MemcachedResult res) {
     if (LOG_ENABLED(INFO)) {
       LOG(INFO) << "Memcached: session cache done.  key=" << req->key
-                << ", status_code=" << res.status_code << ", value="
+                << ", status_code=" << static_cast<uint16_t>(res.status_code)
+                << ", value="
                 << std::string(std::begin(res.value), std::end(res.value));
     }
-    if (res.status_code != 0) {
+    if (res.status_code != MemcachedStatusCode::NO_ERROR) {
       LOG(WARN) << "Memcached: failed to cache session key=" << req->key
-                << ", status_code=" << res.status_code << ", value="
+                << ", status_code=" << static_cast<uint16_t>(res.status_code)
+                << ", value="
                 << std::string(std::begin(res.value), std::end(res.value));
     }
   };
@@ -404,7 +406,8 @@ SSL_SESSION *tls_session_get_cb(SSL *ssl,
       util::format_hex(balloc, StringRef{id, static_cast<size_t>(idlen)});
   req->cb = [conn](MemcachedRequest *, MemcachedResult res) {
     if (LOG_ENABLED(INFO)) {
-      LOG(INFO) << "Memcached: returned status code " << res.status_code;
+      LOG(INFO) << "Memcached: returned status code "
+                << static_cast<uint16_t>(res.status_code);
     }
 
     // We might stop reading, so start it again
@@ -415,7 +418,7 @@ SSL_SESSION *tls_session_get_cb(SSL *ssl,
     ev_timer_again(conn->loop, &conn->wt);
 
     conn->tls.cached_session_lookup_req = nullptr;
-    if (res.status_code != 0) {
+    if (res.status_code != MemcachedStatusCode::NO_ERROR) {
       conn->tls.handshake_state = TLSHandshakeState::CANCEL_SESSION_CACHE;
       return;
     }
diff --git a/src/shrpx_worker_process.cc b/src/shrpx_worker_process.cc
index 6af4563a..dc95701f 100644
--- a/src/shrpx_worker_process.cc
+++ b/src/shrpx_worker_process.cc
@@ -275,9 +275,9 @@ void memcached_get_ticket_key_cb(struct ev_loop *loop, ev_timer *w,
   req->op = MemcachedOp::GET;
   req->cb = [conn_handler, w](MemcachedRequest *req, MemcachedResult res) {
     switch (res.status_code) {
-    case MEMCACHED_ERR_NO_ERROR:
+    case MemcachedStatusCode::NO_ERROR:
       break;
-    case MEMCACHED_ERR_EXT_NETWORK_ERROR:
+    case MemcachedStatusCode::EXT_NETWORK_ERROR:
       conn_handler->on_tls_ticket_key_network_error(w);
       return;
     default: