diff --git a/auto/os/linux b/auto/os/linux
index a0c8795bb..e4aa0e549 100644
--- a/auto/os/linux
+++ b/auto/os/linux
@@ -157,6 +157,37 @@ ngx_feature_test="if (prctl(PR_SET_DUMPABLE, 1, 0, 0, 0) == -1) return 1"
 . auto/feature
 
 
+# prctl(PR_SET_KEEPCAPS)
+
+ngx_feature="prctl(PR_SET_KEEPCAPS)"
+ngx_feature_name="NGX_HAVE_PR_SET_KEEPCAPS"
+ngx_feature_run=yes
+ngx_feature_incs="#include <sys/prctl.h>"
+ngx_feature_path=
+ngx_feature_libs=
+ngx_feature_test="if (prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0) == -1) return 1"
+. auto/feature
+
+
+# capabilities
+
+ngx_feature="capabilities"
+ngx_feature_name="NGX_HAVE_CAPABILITIES"
+ngx_feature_run=no
+ngx_feature_incs="#include <sys/capability.h>"
+ngx_feature_path=
+ngx_feature_libs=
+ngx_feature_test="struct __user_cap_data_struct    data;
+                  struct __user_cap_header_struct  header;
+
+                  header.version = _LINUX_CAPABILITY_VERSION_3;
+                  data.effective = CAP_TO_MASK(CAP_NET_RAW);
+                  data.permitted = 0;
+
+                  (void) capset(&header, &data)"
+. auto/feature
+
+
 # crypt_r()
 
 ngx_feature="crypt_r()"
diff --git a/src/core/ngx_cycle.h b/src/core/ngx_cycle.h
index 2b48ccbd6..a825da2f9 100644
--- a/src/core/ngx_cycle.h
+++ b/src/core/ngx_cycle.h
@@ -114,6 +114,8 @@ typedef struct {
 
     ngx_array_t               env;
     char                    **environment;
+
+    ngx_uint_t                transparent;  /* unsigned  transparent:1; */
 } ngx_core_conf_t;
 
 
diff --git a/src/http/ngx_http_upstream.c b/src/http/ngx_http_upstream.c
index 6d0f4ee52..f8d5707d3 100644
--- a/src/http/ngx_http_upstream.c
+++ b/src/http/ngx_http_upstream.c
@@ -6078,6 +6078,12 @@ ngx_http_upstream_bind_set_slot(ngx_conf_t *cf, ngx_command_t *cmd,
     if (cf->args->nelts > 2) {
         if (ngx_strcmp(value[2].data, "transparent") == 0) {
 #if (NGX_HAVE_TRANSPARENT_PROXY)
+            ngx_core_conf_t  *ccf;
+
+            ccf = (ngx_core_conf_t *) ngx_get_conf(cf->cycle->conf_ctx,
+                                                   ngx_core_module);
+
+            ccf->transparent = 1;
             local->transparent = 1;
 #else
             ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
diff --git a/src/os/unix/ngx_linux_config.h b/src/os/unix/ngx_linux_config.h
index 2f6129d88..b22ea4378 100644
--- a/src/os/unix/ngx_linux_config.h
+++ b/src/os/unix/ngx_linux_config.h
@@ -99,6 +99,11 @@ typedef struct iocb  ngx_aiocb_t;
 #endif
 
 
+#if (NGX_HAVE_CAPABILITIES)
+#include <sys/capability.h>
+#endif
+
+
 #define NGX_LISTEN_BACKLOG        511
 
 
diff --git a/src/os/unix/ngx_process_cycle.c b/src/os/unix/ngx_process_cycle.c
index a20a515c7..40654b3a2 100644
--- a/src/os/unix/ngx_process_cycle.c
+++ b/src/os/unix/ngx_process_cycle.c
@@ -839,12 +839,44 @@ ngx_worker_process_init(ngx_cycle_t *cycle, ngx_int_t worker)
                           ccf->username, ccf->group);
         }
 
+#if (NGX_HAVE_PR_SET_KEEPCAPS && NGX_HAVE_CAPABILITIES)
+        if (ccf->transparent && ccf->user) {
+            if (prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0) == -1) {
+                ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
+                              "prctl(PR_SET_KEEPCAPS, 1) failed");
+                /* fatal */
+                exit(2);
+            }
+        }
+#endif
+
         if (setuid(ccf->user) == -1) {
             ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
                           "setuid(%d) failed", ccf->user);
             /* fatal */
             exit(2);
         }
+
+#if (NGX_HAVE_CAPABILITIES)
+        if (ccf->transparent && ccf->user) {
+            struct __user_cap_data_struct    data;
+            struct __user_cap_header_struct  header;
+
+            ngx_memzero(&header, sizeof(struct __user_cap_header_struct));
+            ngx_memzero(&data, sizeof(struct __user_cap_data_struct));
+
+            header.version = _LINUX_CAPABILITY_VERSION_3;
+            data.effective = CAP_TO_MASK(CAP_NET_RAW);
+            data.permitted = data.effective;
+
+            if (capset(&header, &data) == -1) {
+                ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
+                              "capset() failed");
+                /* fatal */
+                exit(2);
+            }
+        }
+#endif
     }
 
     if (worker >= 0) {
diff --git a/src/stream/ngx_stream_proxy_module.c b/src/stream/ngx_stream_proxy_module.c
index ad81cc8b7..818d7329b 100644
--- a/src/stream/ngx_stream_proxy_module.c
+++ b/src/stream/ngx_stream_proxy_module.c
@@ -2155,6 +2155,12 @@ ngx_stream_proxy_bind(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
     if (cf->args->nelts > 2) {
         if (ngx_strcmp(value[2].data, "transparent") == 0) {
 #if (NGX_HAVE_TRANSPARENT_PROXY)
+            ngx_core_conf_t  *ccf;
+
+            ccf = (ngx_core_conf_t *) ngx_get_conf(cf->cycle->conf_ctx,
+                                                   ngx_core_module);
+
+            ccf->transparent = 1;
             local->transparent = 1;
 #else
             ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,