diff --git a/src/array.c b/src/array.c
index a317951d..a73fc763 100644
--- a/src/array.c
+++ b/src/array.c
@@ -400,7 +400,7 @@ array_match_key_prefix_nc_klen (const array * const a, const char * const s, con
     for (size_t i = 0; i < a->used; ++i) {
         const buffer * const key = a->data[i]->key;
         const size_t klen = buffer_string_length(key);
-        if (klen <= slen && 0 == strncasecmp(s, key->ptr, klen))
+        if (klen <= slen && buffer_eq_icase_ssn(s, key->ptr, klen))
             return a->data[i];
     }
     return NULL;
@@ -440,7 +440,7 @@ array_match_value_prefix_nc (const array * const a, const buffer * const b)
     for (size_t i = 0; i < a->used; ++i) {
         const buffer * const value = ((data_string *)a->data[i])->value;
         const size_t vlen = buffer_string_length(value);
-        if (vlen <= blen && 0 == strncasecmp(b->ptr, value->ptr, vlen))
+        if (vlen <= blen && buffer_eq_icase_ssn(b->ptr, value->ptr, vlen))
             return value;
     }
     return NULL;
@@ -470,7 +470,7 @@ array_match_key_suffix_nc (const array * const a, const buffer * const b)
     for (size_t i = 0; i < a->used; ++i) {
         const buffer * const key = a->data[i]->key;
         const size_t klen = buffer_string_length(key);
-        if (klen <= blen && 0 == strncasecmp(end - klen, key->ptr, klen))
+        if (klen <= blen && buffer_eq_icase_ssn(end - klen, key->ptr, klen))
             return a->data[i];
     }
     return NULL;
@@ -500,7 +500,7 @@ array_match_value_suffix_nc (const array * const a, const buffer * const b)
     for (size_t i = 0; i < a->used; ++i) {
         const buffer * const value = ((data_string *)a->data[i])->value;
         const size_t vlen = buffer_string_length(value);
-        if (vlen <= blen && 0 == strncasecmp(end - vlen, value->ptr, vlen))
+        if (vlen <= blen && buffer_eq_icase_ssn(end - vlen, value->ptr, vlen))
             return value;
     }
     return NULL;
diff --git a/src/http-header-glue.c b/src/http-header-glue.c
index b7f03309..d54f00cf 100644
--- a/src/http-header-glue.c
+++ b/src/http-header-glue.c
@@ -19,7 +19,6 @@
 
 #include <time.h>
 
-#include "sys-strings.h"
 #include "sys-socket.h"
 #include <unistd.h>
 
@@ -641,7 +640,7 @@ static void http_response_xsendfile (server *srv, connection *con, buffer *path,
 			if (dlen <= xlen
 			    && (!con->conf.force_lowercase_filenames
 				? 0 == memcmp(path->ptr, ds->value->ptr, dlen)
-				: 0 == strncasecmp(path->ptr, ds->value->ptr, dlen))) {
+				: buffer_eq_icase_ssn(path->ptr, ds->value->ptr, dlen))) {
 				break;
 			}
 		}
@@ -715,7 +714,7 @@ static void http_response_xsendfile2(server *srv, connection *con, const buffer
                 if (dlen <= xlen
                     && (!con->conf.force_lowercase_filenames
                     ? 0 == memcmp(b->ptr, ds->value->ptr, dlen)
-                    : 0 == strncasecmp(b->ptr, ds->value->ptr, dlen))) {
+                    : buffer_eq_icase_ssn(b->ptr, ds->value->ptr, dlen))) {
                     break;
                 }
             }
@@ -985,8 +984,11 @@ static int http_response_process_headers(server *srv, connection *con, http_resp
                         con->http_status = 502; /* Bad Gateway */
                         break;
                     }
-                } else if (id == HTTP_HEADER_OTHER && key_len > 9
-                           && 0==strncasecmp(key, CONST_STR_LEN("Variable-"))) {
+                }
+                else if (id == HTTP_HEADER_OTHER && key_len > 9
+                         && (key[0] & 0xdf) == 'V'
+                         && buffer_eq_icase_ssn(key,
+                                                CONST_STR_LEN("Variable-"))) {
                     http_header_env_append(con, key + 9, key_len - 9, value, strlen(value));
                 }
                 continue;
diff --git a/src/mod_proxy.c b/src/mod_proxy.c
index a6b05b83..3336fab1 100644
--- a/src/mod_proxy.c
+++ b/src/mod_proxy.c
@@ -309,7 +309,7 @@ static const buffer * http_header_remap_host_match (buffer *b, size_t off, http_
                 if (NULL == k) continue;
                 mlen = buffer_string_length(k);
             }
-            if (mlen == alen && 0 == strncasecmp(s, k->ptr, alen)) {
+            if (buffer_eq_icase_ss(s, alen, k->ptr, mlen)) {
                 if (buffer_is_equal_string(ds->value, CONST_STR_LEN("-"))) {
                     return remap_hdrs->http_host;
                 }
@@ -462,7 +462,7 @@ static void http_header_remap_setcookie (buffer *b, size_t off, http_header_rema
             ++e;
             switch ((int)(e - s - 1)) {
               case 4:
-                if (0 == strncasecmp(s, "path", 4)) {
+                if (buffer_eq_icase_ssn(s, "path", 4)) {
                     if (*e == '"') ++e;
                     if (*e != '/') continue;
                     off = (size_t)(e - b->ptr);
@@ -472,7 +472,7 @@ static void http_header_remap_setcookie (buffer *b, size_t off, http_header_rema
                 }
                 break;
               case 6:
-                if (0 == strncasecmp(s, "domain", 6)) {
+                if (buffer_eq_icase_ssn(s, "domain", 6)) {
                     size_t alen = 0;
                     if (*e == '"') ++e;
                     if (*e == '.') ++e;
diff --git a/src/mod_ssi.c b/src/mod_ssi.c
index eefd2944..00ac727a 100644
--- a/src/mod_ssi.c
+++ b/src/mod_ssi.c
@@ -17,7 +17,6 @@
 
 #include <sys/types.h>
 #include <sys/stat.h>
-#include "sys-strings.h"
 #include <sys/wait.h>
 
 #include <ctype.h>
@@ -574,7 +573,7 @@ static int process_ssi_stmt(server *srv, connection *con, handler_ctx *p, const
 			if (!con->conf.force_lowercase_filenames
 			    ? buffer_is_equal_right_len(con->physical.path, con->physical.rel_path, remain)
 			    :(buffer_string_length(con->physical.path) >= remain
-			      && 0 == strncasecmp(con->physical.path->ptr+buffer_string_length(con->physical.path)-remain, con->physical.rel_path->ptr+i, remain))) {
+			      && buffer_eq_icase_ssn(con->physical.path->ptr+buffer_string_length(con->physical.path)-remain, con->physical.rel_path->ptr+i, remain))) {
 				buffer_copy_string_len(p->stat_fn, con->physical.path->ptr, buffer_string_length(con->physical.path)-remain);
 				buffer_append_string_len(p->stat_fn, srv->tmp_buf->ptr+i, buffer_string_length(srv->tmp_buf)-i);
 			} else {
diff --git a/src/response.c b/src/response.c
index 4ef569a9..9682f3e9 100644
--- a/src/response.c
+++ b/src/response.c
@@ -227,7 +227,7 @@ static handler_t http_response_physical_path_check(server *srv, connection *con)
 			size_t len = strlen(pathinfo), reqlen;
 			if (con->conf.force_lowercase_filenames
 			    && len <= (reqlen = buffer_string_length(con->request.uri))
-			    && 0 == strncasecmp(con->request.uri->ptr + reqlen - len, pathinfo, len)) {
+			    && buffer_eq_icase_ssn(con->request.uri->ptr + reqlen - len, pathinfo, len)) {
 				/* attempt to preserve case-insensitive PATH_INFO
 				 * (works in common case where mod_alias, mod_magnet, and other modules
 				 *  have not modified the PATH_INFO portion of request URI, or did so
diff --git a/src/stat_cache.c b/src/stat_cache.c
index 4e7ebf37..1cd27657 100644
--- a/src/stat_cache.c
+++ b/src/stat_cache.c
@@ -639,7 +639,7 @@ const buffer * stat_cache_mimetype_by_ext(const connection *con, const char *nam
             /* suffix match */
             const data_string *ds = (data_string *)con->conf.mimetypes->data[i];
             const size_t klen = buffer_string_length(ds->key);
-            if (klen <= nlen && 0 == strncasecmp(end-klen, ds->key->ptr, klen))
+            if (klen <= nlen && buffer_eq_icase_ssn(end-klen, ds->key->ptr, klen))
                 return ds->value;
         }
     }