--- a/src/http/ngx_http_core_module.c
+++ b/src/http/ngx_http_core_module.c
@@ -1672,6 +1672,10 @@ ngx_http_gzip_ok(ngx_http_request_t *r)
 
     clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);
 
+    if (r->headers_in.msie6 && clcf->gzip_disable_msie6) {
+        return NGX_DECLINED;
+    }
+
     if (r->http_version < clcf->gzip_http_version) {
         return NGX_DECLINED;
     }
@@ -2677,6 +2681,7 @@ ngx_http_core_create_loc_conf(ngx_conf_t
     lcf->gzip_http_version = NGX_CONF_UNSET_UINT;
 #if (NGX_PCRE)
     lcf->gzip_disable = NGX_CONF_UNSET_PTR;
+    lcf->gzip_disable_msie6 = 3;
 #endif
 #endif
 
@@ -2914,6 +2919,11 @@ ngx_http_core_merge_loc_conf(ngx_conf_t 
     ngx_conf_merge_ptr_value(conf->gzip_disable, prev->gzip_disable, NULL);
 #endif
 
+    if (conf->gzip_disable_msie6 == 3) {
+        conf->gzip_disable_msie6 =
+            (prev->gzip_disable_msie6 == 3) ? 0 : prev->gzip_disable_msie6;
+    }
+
 #endif
 
     return NGX_CONF_OK;
@@ -3753,8 +3763,9 @@ ngx_http_core_resolver(ngx_conf_t *cf, n
 static char *
 ngx_http_gzip_disable(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
 {
+    ngx_http_core_loc_conf_t  *clcf = conf;
+
 #if (NGX_PCRE)
-    ngx_http_core_loc_conf_t  *clcf = conf;
 
     ngx_str_t         err, *value;
     ngx_uint_t        i;
@@ -3776,6 +3787,11 @@ ngx_http_gzip_disable(ngx_conf_t *cf, ng
 
     for (i = 1; i < cf->args->nelts; i++) {
 
+        if (ngx_strcmp(value[1].data, "msie6") == 0) {
+            clcf->gzip_disable_msie6 = 1;
+            continue;
+        }
+
         re = ngx_array_push(clcf->gzip_disable);
         if (re == NULL) {
             return NGX_CONF_ERROR;
@@ -3795,8 +3811,18 @@ ngx_http_gzip_disable(ngx_conf_t *cf, ng
     return NGX_CONF_OK;
 
 #else
+    ngx_str_t  *value;
+
+    value = cf->args->elts;
+
+    if (cf->args->nelts == 2 && ngx_strcmp(value[1].data, "msie6") == 0) {
+        clcf->gzip_disable_msie6 = 1;
+        return NGX_CONF_OK;
+    }
+
     ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
-                       "\"gzip_disable\" requires PCRE library");
+                       "without PCRE library \"gzip_disable\" supports "
+                       "builtin \"msie6\" mask only");
 
     return NGX_CONF_ERROR;
 #endif

--- a/src/http/ngx_http_core_module.h
+++ b/src/http/ngx_http_core_module.h
@@ -242,6 +242,9 @@ struct ngx_http_core_loc_conf_s {
 
     unsigned      auto_redirect:1;
     unsigned      alias:1;
+#if (NGX_HTTP_GZIP)
+    unsigned      gzip_disable_msie6:2;
+#endif
 
     ngx_http_location_tree_node_t   *static_locations;
     ngx_http_core_loc_conf_t       **regex_locations;

--- a/src/http/ngx_http_request.c
+++ b/src/http/ngx_http_request.c
@@ -1290,7 +1290,7 @@ static ngx_int_t
 ngx_http_process_user_agent(ngx_http_request_t *r, ngx_table_elt_t *h,
     ngx_uint_t offset)
 {
-    u_char  *ua, *user_agent;
+    u_char  *user_agent, *msie;
 
     if (r->headers_in.user_agent) {
         return NGX_OK;
@@ -1302,14 +1302,22 @@ ngx_http_process_user_agent(ngx_http_req
 
     user_agent = h->value.data;
 
-    ua = ngx_strstrn(user_agent, "MSIE", 4 - 1);
-
-    if (ua && ua + 8 < user_agent + h->value.len) {
+    msie = ngx_strstrn(user_agent, "MSIE ", 5 - 1);
+
+    if (msie && msie + 7 < user_agent + h->value.len) {
 
         r->headers_in.msie = 1;
 
-        if (ua[4] == ' ' && ua[5] == '4' && ua[6] == '.') {
-            r->headers_in.msie4 = 1;
+        if (msie[6] == '.') {
+
+            switch (msie[5]) {
+            case '4':
+                r->headers_in.msie4 = 1;
+                /* fall through */
+            case '5':
+            case '6':
+                r->headers_in.msie6 = 1;
+            }
         }
 
 #if 0
@@ -1324,6 +1332,7 @@ ngx_http_process_user_agent(ngx_http_req
         r->headers_in.opera = 1;
         r->headers_in.msie = 0;
         r->headers_in.msie4 = 0;
+        r->headers_in.msie6 = 0;
     }
 
     if (!r->headers_in.msie && !r->headers_in.opera) {

--- a/src/http/ngx_http_request.h
+++ b/src/http/ngx_http_request.h
@@ -214,6 +214,7 @@ typedef struct {
     unsigned                          connection_type:2;
     unsigned                          msie:1;
     unsigned                          msie4:1;
+    unsigned                          msie6:1;
     unsigned                          opera:1;
     unsigned                          gecko:1;
     unsigned                          konqueror:1;