diff --git a/src/buffer.c b/src/buffer.c
index 776c7c75..8d3d5165 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -264,6 +264,16 @@ buffer_copy_path_len2 (buffer * const restrict b, const char * const restrict s1
     buffer_append_path_len(b, s2, len2);/*(choice: not inlined, special-cased)*/
 }
 
+void
+buffer_copy_string_len_lc (buffer * const restrict b, const char * const restrict s, const size_t len)
+{
+    char * const restrict d = buffer_string_prepare_copy(b, len);
+    b->used = len+1;
+    d[len] = '\0';
+    for (size_t i = 0; i < len; ++i)
+        d[i] = (!light_isupper(s[i])) ? s[i] : s[i] | 0x20;
+}
+
 void buffer_append_uint_hex_lc(buffer *b, uintmax_t value) {
 	char *buf;
 	unsigned int shift = 0;
diff --git a/src/buffer.h b/src/buffer.h
index cf828a0f..1ebee556 100644
--- a/src/buffer.h
+++ b/src/buffer.h
@@ -107,6 +107,7 @@ void buffer_free_ptr(buffer *b);
 
 void buffer_copy_string(buffer * restrict b, const char * restrict s);
 void buffer_copy_string_len(buffer * restrict b, const char * restrict s, size_t len);
+void buffer_copy_string_len_lc(buffer * restrict b, const char * restrict s, size_t len);
 
 void buffer_append_string(buffer * restrict b, const char * restrict s);
 void buffer_append_string_len(buffer * restrict b, const char * restrict s, size_t len);
diff --git a/src/configfile.c b/src/configfile.c
index 8c6f6397..a673ad99 100644
--- a/src/configfile.c
+++ b/src/configfile.c
@@ -2553,9 +2553,7 @@ int config_set_defaults(server *srv) {
 		s->force_lowercase_filenames = 0; /* default to 0 */
 
 		buffer * const tb = srv->tmp_buf;
-		buffer_copy_buffer(tb, s->document_root);
-
-		buffer_to_lower(tb);
+		buffer_copy_string_len_lc(tb, BUF_PTR_LEN(s->document_root));
 
 		if (0 == stat(tb->ptr, &st1)) {
 			int is_lower = 0;
diff --git a/src/mod_extforward.c b/src/mod_extforward.c
index 74612f5a..7544d42b 100644
--- a/src/mod_extforward.c
+++ b/src/mod_extforward.c
@@ -949,16 +949,15 @@ static handler_t mod_extforward_Forwarded (request_st * const r, plugin_data * c
             while (vlen > v && (s[vlen-1] == ' ' || s[vlen-1] == '\t')) --vlen;
             if (vlen > v+1 && s[v] == '"' && s[vlen-1] == '"') {
                 ++v; --vlen;
-                buffer_copy_string_len(r->http_host, s+v, vlen-v);
+                buffer_copy_string_len_lc(r->http_host, s+v, vlen-v);
                 if (!buffer_backslash_unescape(r->http_host)) {
                     return mod_extforward_bad_request(r, __LINE__,
                       "invalid host= value in Forwarded header");
                 }
             }
             else {
-                buffer_copy_string_len(r->http_host, s+v, vlen-v);
+                buffer_copy_string_len_lc(r->http_host, s+v, vlen-v);
             }
-            buffer_to_lower(r->http_host);
 
             if (0 != http_request_host_policy(r->http_host,
                                               r->conf.http_parseopts,
diff --git a/src/mod_gnutls.c b/src/mod_gnutls.c
index 3ba60e0d..e9a892a2 100644
--- a/src/mod_gnutls.c
+++ b/src/mod_gnutls.c
@@ -1443,8 +1443,7 @@ mod_gnutls_SNI(handler_ctx * const hctx,
     }
 
     /* use SNI to patch mod_gnutls config and then reset COMP_HTTP_HOST */
-    buffer_copy_string_len(&r->uri.authority, (const char *)servername, len);
-    buffer_to_lower(&r->uri.authority);
+    buffer_copy_string_len_lc(&r->uri.authority, (const char *)servername, len);
   #if 0
     /*(r->uri.authority used below for configuration before request read;
      * revisit for h2)*/
diff --git a/src/mod_mbedtls.c b/src/mod_mbedtls.c
index 7068c9fb..8c258706 100644
--- a/src/mod_mbedtls.c
+++ b/src/mod_mbedtls.c
@@ -711,8 +711,7 @@ mod_mbedtls_SNI (void *arg, mbedtls_ssl_context *ssl, const unsigned char *serve
     }
 
     /* use SNI to patch mod_mbedtls config and then reset COMP_HTTP_HOST */
-    buffer_copy_string_len(&r->uri.authority, (const char *)servername, len);
-    buffer_to_lower(&r->uri.authority);
+    buffer_copy_string_len_lc(&r->uri.authority, (const char *)servername, len);
   #if 0
     /*(r->uri.authority used below for configuration before request read;
      * revisit for h2)*/
diff --git a/src/mod_nss.c b/src/mod_nss.c
index db5e63ad..db2b42ee 100644
--- a/src/mod_nss.c
+++ b/src/mod_nss.c
@@ -1393,8 +1393,7 @@ mod_nss_SNI (PRFileDesc *ssl, const SECItem *srvNameArr, PRUint32 srvNameArrSize
     }
 
     /* use SNI to patch mod_nss config and then reset COMP_HTTP_HOST */
-    buffer_copy_string_len(&r->uri.authority, (const char *)sn->data, sn->len);
-    buffer_to_lower(&r->uri.authority);
+    buffer_copy_string_len_lc(&r->uri.authority,(const char *)sn->data,sn->len);
   #if 0
     /*(r->uri.authority used below for configuration before request read;
      * revisit for h2)*/
diff --git a/src/mod_openssl.c b/src/mod_openssl.c
index 6f4539dd..dd34d4cf 100644
--- a/src/mod_openssl.c
+++ b/src/mod_openssl.c
@@ -1190,8 +1190,7 @@ mod_openssl_SNI (handler_ctx *hctx, const char *servername, size_t len)
     }
 
     /* use SNI to patch mod_openssl config and then reset COMP_HTTP_HOST */
-    buffer_copy_string_len(&r->uri.authority, servername, len);
-    buffer_to_lower(&r->uri.authority);
+    buffer_copy_string_len_lc(&r->uri.authority, servername, len);
   #if 0
     /*(r->uri.authority used below for configuration before request read;
      * revisit for h2)*/
diff --git a/src/mod_wolfssl.c b/src/mod_wolfssl.c
index 905f0ecb..96d5b150 100644
--- a/src/mod_wolfssl.c
+++ b/src/mod_wolfssl.c
@@ -1268,8 +1268,7 @@ mod_openssl_SNI (handler_ctx *hctx, const char *servername, size_t len)
     }
 
     /* use SNI to patch mod_openssl config and then reset COMP_HTTP_HOST */
-    buffer_copy_string_len(&r->uri.authority, servername, len);
-    buffer_to_lower(&r->uri.authority);
+    buffer_copy_string_len_lc(&r->uri.authority, servername, len);
   #if 0
     /*(r->uri.authority used below for configuration before request read;
      * revisit for h2)*/
diff --git a/src/request.c b/src/request.c
index 523a7f89..d10774f6 100644
--- a/src/request.c
+++ b/src/request.c
@@ -270,8 +270,7 @@ static void http_request_header_set_Host(request_st * const restrict r, const ch
 {
     r->http_host = http_header_request_set_ptr(r, HTTP_HEADER_HOST,
                                                CONST_STR_LEN("Host"));
-    buffer_copy_string_len(r->http_host, h, hlen);
-    buffer_to_lower(r->http_host);
+    buffer_copy_string_len_lc(r->http_host, h, hlen);
 }
 
 
diff --git a/src/response.c b/src/response.c
index c139e2db..6aca7b60 100644
--- a/src/response.c
+++ b/src/response.c
@@ -622,10 +622,8 @@ static handler_t http_response_comeback (request_st * const r)
 
     request_config_reset(r);
 
-    if (__builtin_expect( (r->http_host != NULL), 1)) {
-        buffer_copy_buffer(&r->uri.authority, r->http_host);
-        buffer_to_lower(&r->uri.authority);
-    }
+    if (__builtin_expect( (r->http_host != NULL), 1))
+        buffer_copy_string_len_lc(&r->uri.authority, BUF_PTR_LEN(r->http_host));
     else /*(buffer_blank(&r->uri.authority) w/o code inline)*/
         buffer_copy_string_len(&r->uri.authority, CONST_STR_LEN(""));