diff --git a/src/http/ngx_http_core_module.c b/src/http/ngx_http_core_module.c
index 9d614d450..e79dd1cd2 100644
--- a/src/http/ngx_http_core_module.c
+++ b/src/http/ngx_http_core_module.c
@@ -2566,6 +2566,10 @@ ngx_http_core_regex_location(ngx_conf_t *cf, ngx_http_core_loc_conf_t *clcf,
     err.len = NGX_MAX_CONF_ERRSTR;
     err.data = errstr;
 
+#if (NGX_HAVE_CASELESS_FILESYSTEM)
+    caseless = 1;
+#endif
+
     clcf->regex = ngx_regex_compile(regex, caseless ? NGX_REGEX_CASELESS: 0,
                                     cf->pool, &err);
 
diff --git a/src/os/win32/ngx_files.h b/src/os/win32/ngx_files.h
index af56800d5..950bd98a2 100644
--- a/src/os/win32/ngx_files.h
+++ b/src/os/win32/ngx_files.h
@@ -149,6 +149,7 @@ ngx_int_t ngx_file_info(u_char *filename, ngx_file_info_t *fi);
                                | (fi)->ftLastWriteTime.dwLowDateTime)        \
                                           - 116444736000000000) / 10000000)
 
+#define NGX_HAVE_CASELESS_FILESYSTEM  1
 
 #define ngx_filename_cmp(s1, s2, n) _strnicmp((char *) s1, (char *) s2, n)